Here are the materials you will need for this stool:

4, 30-inch 2x4 (pieces of wood)
2, 13-inch 1x1
4, 8.5-inch 1x1
1, 14.5-inch 1x1
1, 17-inch diameter Medium-density fibreboard
4, 16x8.5 inch square tan fabric
1, 21-inch radius red with white dot pattern fabric
16 inch diameter pillow
16 mini velcros
L-brackets

Other items for use:

Screws
Power drill (Along with drill bit and screw bits)
Wood glue
Ruler
Power sander
Tablesaw

NOTE: Pieces of woods listed with dimensions can be cut out from larger pieces (ie: cutting a 60-inch 2x4 in half for 2, 30-inch)

Step 1: Creating the Legs

First, start off with your 2x4 piece of wood. You will need 4 of these cut to a length of 30 inches. These will serve as your legs.
To make the legs slanted, cut at a 7-degree angle perpendicular to the short length of the base of the wood. This will need to be done to both sides so the bases of the piece will be parallel.

Step 2: Creating the Cross

In order to connect the legs, there will be a cross that will hold the 4 legs together.

Start with 2 1x1 pieces of wood that are 13 inches long. Mark up a 1/2 inch by 3/2 inch box from the edge of the long side of the 1x1.

To cut out the square, start by making multiple small cuts from the ledge to the inside of the box drawn.

After a few cuts start chiseling out the pieces of wood and sand the inside until the two pieces of wood can fit together.

In order for the cross to be able to fit with the legs, make a 7-degree cut at the sides of the 1x1. The 7-degree cuts should be pointing towards each other and not parallel to make a frustum shape.

Apply wood glue to connect the pieces and use clamps to apply pressure and make sure they dry correctly

Step 3: Connecting the Legs and Cross

Start off by locating where the cross will need to be. This will be about midway up the stool so it will be connected with the legs 15 inches from the ground.

Drill holes before any type of screwing.

To ensure the holes match up, woodglue them together first before drilling. The wood glue doesn't have to be completely dry but as long as it can hold the pieces together so that it is easier to drill. This way, the drill can go through the legs and cross to ensure the holes are aligned.

Use a power drill to apply a screw into the legs and cross and repeat this process for the other legs. Your stool should be able to stand after this.

Step 4: Creating and Connecting Leg Connectors

Cut 4, 1x1s to 8.5 inches.

Cut the two sides at a 45-degree angle so that they are pointing towards each other.

Repeat this for all pieces

Attach these connectors at the center of the way up so they are parallel horizontally with the cross.

Mark up where you will place them and cut off the excess to make the width of the connector the same as the length of the leg.

Glue them together and drill a hole from the connector into the leg.

Screw the connectors and legs together.

Step 5: Adding the Bottom Leg

Cut out a 14.5 inch 1x1

Flip the stool over and glue the 1x1 to the center of the cross

Use 2 L-brackets on opposite sides to attach the 5th leg.

To attach the L-brackets, line them up with the leg and the bottom of the cross and draw in the holes.

Drill and screw to connect the L-brackets

Step 6: Sanding and Leveling Your Stool

Sand the base of the legs to make sure your legs are as even and flat as possible.

Sand the faces of the stool to smoothen out the surfaces and to get rid of any potential splinters.

Doing this manually is a hassle so a power sander is recommended.

Step 7: Attaching the Seat

Cut out a 17-inch diameter circle from a medium density fibreboard that is 0.75 inches thick.

Mark up the board to match the base of the legs. The outside edges of the boxes should be 5.75 inches from the center of the board.

Glue the legs to the board to stabilize the drilling process.

Drill and apply screws to connect the seat.

Step 8: Making It Sturdy

Attach L-brackets from the cross to the inside of the legs. Mark the holes, drill, and screw.

Apply a second screw from the leg to the cross.

These two steps will secure the twisting of the legs and make it sturdier.

Step 9: Design

Cut out a 22 inch radius circle from your red with white dots fabric.
Cut out 4, 16x16-inch rectangles from your tan fabric.
Using the velcro stickers attach the pillow to the seat.
Also using the velcro, attack the red fabric to the pillow and tan fabric to the leg connectors.