What do you do with a spare back cushion for a sofa and a shed full of woodwork tools? You might be thinking overly aggressive pillow fight or maybe a terrifying scarecrow, but how about a footstool...*ooohs and ahhs from gathered crowd*.

Any way, my Grandad had a whole collection of woodwork tools in his shed so I thought I'd give it a go at my first joints! I'm not really sure how you're meant to make them but this is how I managed to do it.

I made this footstool for my mum to match her sofa. It's great at the size that we used but can be scaled to fit different sofas or just to suit you exactly. I have included a lift off top to give storage in the bottom but it could be easily adapted to have a fixed or hinged top.

Step 1: Cut to Length

What you need:

A spare back cushion from your sofa - because everyone has those lying around! A similar size foam pad would work brilliantly. (the cushion that I had was 700x480x150mm)
8 thin metal brackets, about 1cm wide. - I got these from B and Q
16 screws, 5 mm length, to fit brackets, some packs include these
8 nails, longer than 30mm, to attach to batons to the lid.
6 felt pads, to use as feet
2 pieces of hardboard, 400 x 290mm
2 pieces of hardboard, 620 x 290mm, all of the hardboard is a case to put around the frame
6 lengths of 30 x 30 pine, 280mm. These are the uprights, for the corners and middle.
2 lengths of 30 x 30 pine, 400mm. These are the short sides, at the top of the frame
2 lengths of 30 x 30 pine, 620mm. These are the long sides, at the top of the frame
2 lengths of 30 x 30 pine, 210mm. These are the short batons on the lid
2 lengths of 30 x 30 pine, 300mm. These are the long batons on the lid
2 pieces of 10mm MDF, 400 x 620mm. These will be the top and bottom pieces.
A length of dowel or 12 pre cut dowels, about 5mm diameter
A chisel, the sharper the better
A hammer
A nail gun, tacks can be used instead though
Strong, plain fabric to secure the cushion onto the lid, about 1m should do.

You will also need about 1m of velcro and some fabric - my current estimate is 3m but I'll update this when I have finished the cover.

I got all of my wood cut at B&Q for free when I was buying them. I was really impressed with them and they even helped me find the best deals! This is really good so that you don't have to cut long, straight lines.

Step 2: Mark Out and Make the Mortise

Ok, I made this foot stool by making a frame with mortise and tenon joints around the top.

I found it best to roughly put it together first and number the uprights then put the corresponding number on each edge of the other pieces, sometimes with a letter to make it clearer which way round it goes. This is particularly important when it comes to finishing the mortise and tennon joints.

On the top of each upright, mark out the area for the mortise (hole) by marking out the size of the wood it is being joined to and finding the middle. Then draw a 10mm square around the middle. The size of the posts is handy here as they are 30mm wide, they can be easily split into 3 10mm sections to create the square.

To start making the hole, put your chisel, with the flat edge slightly inside the line, and the bevel pointing inwards, and tap it in. Go around the square a couple of times, just making a clear edge then break up the wood inside and gently prize it out. Carry this on until you get a good distance down (maybe 10mm), then turn it over and start on the second mortise of that post. These should be at right angles to each other and I found that they meet easily.

Tidy up the inside edges of the mortice and then repeat this on all of the uprights.

Step 3: Mark Out and Cut the Tenon

Next you can make the tenon (stick) of the joint. The first thing to do is to mark out the joint. Make sure that the distance between the two joints is the same as the distance between the two uprights. Then mark out a 10mm post in the middle of each face. Saw each face down to the top line on the sides.

Mark out a 10mm square in the middle of each end of the wood. Stand it upright and, using a chisel, carefully remove the edges until you are left with a rough 10mm square.

It is important now that the pieces are fit to their mate because each joint will be slightly different and, for the best fit, they need to be shaped for each hole individually. - I forgot that it matters which mortise of the upright you put it into and had to fudge a couple of the joints.

I found it easier to cut the tenon down rather than making the mortise bigger so put the joint together and check where the tenon needs cutting down. Be careful that you take wood off the right side of the tenon otherwise the joint will end up uneven. You can see which side to take away from by lining the mortise up with the side of the tenon and the edge of wood and seeing where is too close.

Shave a little off at a time using the chisel, making sure that it is upright, and keep checking it against your mortise.

Step 4: Cut Chamfer Onto Tennon

Now you need to cut a chamfer onto the tenons, these need to be 45 degrees and if you have an angle guide, just line up your saw with the edge of the post and cut at 45 degrees. Make sure that you cut the angle on the right edge and that it is the right way round. I did this by roughly assembling it again and drawing the angles on so that they would match inside the joint as in the picture above.

Once you have cut the angle into the joint, fit each of them together and check that they fit snugly. If not then adjust the joint slowly and keep checking it together.

If you are confident in your joints then it isn't necessary to include brackets too. I don't have any practice of joints, these are my first, so I'm using brackets and dowels and everything! The brackets need to be attached to the same faces of the posts as the mortises so that they are inside the box.

Step 5: Drill Holes and Insert Dowels

Now it's time to glue the joints together. They don't need much pressure to keep them still while they dry but I found it easier to use my work mate. I assembled it upside down, starting with the short sides and then adding them to the long sides and holding it still in the work mate

And next, its the dowels. These probably don't add anything, considering the brackets but hey, I like them!! Carefully align the posts with each corner. Drill through the base, into the post and glue a dowel into place. I started screwing in one bracket on each corner while it was upside down before cutting off the dowel and turning it the right way around. This was rather difficult and, if you measure the length of dowel needed and cut each one this would probably be easier but I also found that I can't cut dowels neatly! I did turn it the right way up to fix in the rest of the screws, much better.

Once the corners are fixed, you can mark and cut the middle uprights to size and put dowels in those like with the corners. Be careful when drilling into the upright, it tends to like turning with the drill.

I went a little crazy at this stage, sanding the top of the frame to get rid of all of the wobbles...then I realized that there will be a couple of layers of fabric between the frame and the lid and that would probably stop the wobble!

Step 6: Secure the Cushion

I had a left over back cushion from the sofa but, if you don't, a foam pad would be perfect. It needs to be slightly bigger then the lid so that it overlaps. Any strong, preferably plain, fabric is great for fixing the cushion on, I used an old blackout blind. Secure each side in the middle with a staple or tack then carefully fold the corner so that there isn't any bunching. Make sure that you pull the fabric tight and try to keep the fabric from wrinkling when you attach it. Add enough tacks or staples so that you are confident that it is secure.

Then put the lid on top of the frame and line up the edges of the lid with the frame. Mark the inside of the frame onto the lid. Here it is particularly helpful to have neat fabric just so that it doesn't move.

Step 7: Attach the Batons

Carefully align the batons inside the line that you have just made and nail them into place. This is rather difficult with the cushion underneath it so start them into the baton when its on a table and see if you can get a mate to push down on the lid when putting them in.

Its then time to attach the hardboard to the sides of the frame using staples or tacks. Start with the corners and then add more in to secure it further. Once they are all attached, sand down the edges of the hardboard to match the frame and add the felt pads to the base of the stool.

You could attach the hardboard to the inside of the frame if you want a flush interior.

Finally, just test the fit of the lid and sand down the batons as needed. Also sand down the corners to get rid of the sharp edges, they are sneakily painful!

Step 8: Add the Cover

This is it in place, with a couple of blankets thrown over - until I finish the cover.

In the second picture, I've just fixed the bottom fabric with the lid to give the effect but I haven't settled on a fabric yet. when I do, this will be stapled on and then I'll stitch a cover for the top and attach it on with velcro so that it is removable. I'll update this with pictures and any instructions as I make them...keep checking back!!