This is the very first serious sewing project I have done and I would encourage you guys to make it your first as well. It is relatively simple to make and you don't need to buy a pattern as long as you have a pair of pants handy that fit you well. I made mine from a thick fleece material I had left over from making a Deadmau5 head so they were more like yoga or sweat pants. I have been wearing them every day and love them.
Step 1: Materials
You will need:
A sewing machine. A sewing machine is not essential but it will make your life a good deal easier. It doesn't have to be anything fancy and you could probably get one at your local used store for less than $30. Another option would be to borrow it from a friend. In either case chances are the manual is long gone and you won't know how to thread it. A quick Google search of the serial number will help you enormously.
About two yards of cloth. I used a fleece material that I had left over from my Deadmau5 head so it was like a pair of yoga or sweatpants. I recommend flannel but really anything will do.
A spool of thread to match the color of your cloth.
A pair of pants that fit you well.
A very large piece of paper. You should be able to wrap it around yourself at the waist and it should reach the floor.
Elastic. If you don't want to buy it you can scavenge it from an old pair of shorts, pants or underwear.
Step 2: Making the Pattern
Fold your pants in half so both sides of the front are facing out. Make sure the seams on the side are on the edge and then place them on your piece of paper. Trace a line a half inch away from the pants and one even with them. For the bottom of the legs and the waist make it an inch and a half. Don't follow the curves and undulations of the folded pants but keep the line straight except where the pants actually curve (in my case the inseam). Do this for the back of your pants as well. It is important to do both sides because they are not the same size and shape.
Step 3: Cutting the Fabric
Pin your cutout patterns to the cloth. Fold the cloth so it is two layers thick to make them exactly the same size and shape. Cut as straight as possible to make it easier to sew later on. Then mark the cut pieces front or back.
Step 4: Sewing the Inseam
Put the two front pieces together so they are lined up and sew the inseam. Marking the sewing line with chalk helps a lot. Tie the thread ends so it doesn't unravel. Do the same to the back pieces.
Step 5: Sewing the Sides
Place the two pieces you have now so that if they were attached it would be inside out. Mark your line with chalk again. Sew the seam on the inside of your legs first. When you cross the area where all four pieces meet trim of any excess material and get it as flat as possible so there isn't a big lump there. Then sew the outside seam. With these all together you can try them on now and make sure it fits well. There should be a little excess of the waist and legs for the hem and waistband.
Step 6: Making the Waistband
With your piece of elastic find a length that is comfortable when stretched all the way around your waist. Fold the waist down enough to let the elastic fit in there and sew it down (the pants should be inside out again). Then stick the elastic in and guide it though the tube by pushing the fabric over it and then pulling it through. Make sure that the elastic stays flat and doesn't flip over. Once you have don that sew the elastic down on the seams.
Step 7: Hemming the Pants
This part is pretty easy. Put the pants on and then roll them up until they are at a good length. Measure how much and then roll them up while it is turned inside out. After that you just sew about a quarter inch away from the bottom.
Step 8: You're Done
They're done now. Enjoy.