I used 19 different fabrics including the red, white & blue solids. I used black thread. You also need large eyelets (buy the kit so you have the eyelet tool). I used a dozen. Those will be the last thing you do to your curtain besides hang it.
Cut out 9"x9" squares of your fabric. Cotton seems to do the best and you do not want to choose any fabric that will "bleed" onto your others when it's washed. (Do not cut with pinking shears but regular scissors as you will want your edges to fray.) You decide how many of each you would like for your curtain. I like mine to be very random.
After your squares are all cut you lay them out on the floor in whatever pattern you like. You need at least 9 squares across but you may need more- it depends on your shower or bath opening. You need at least 11 down but then again, you may need more. I have made a couple more of these as gifts that were short & I had to add squares but it's easier to add the squares then to take them off. Keep in mind you will be taking in 1" all the way around your squares for the fringe. You can measure your opening and if your making one for yourself, you should be able to gage how many inches you will need across & down.
Once your pattern is laid out how you want it you will need to pin the top row of squares to together, this will be the top of your shower curtain. Pin each row but do not pin them to the next row. Begin sewing. I like to sew all the squares for all horizontal rows together first. Once they are sewed, you will pin them to the next row (one row at a time). Then take each row and sew it to the next, working your way to the bottom of the curtain. Make sure your folding your rag edge in to the front of the fabric as the backside will be the back of the fabric and against a liner curtain so it will not show. (photo of backside) Once the curtain is completely sewed together you will then snip all the turned in edges that will be fringe. After it's completely snipped you will wash it on cold. It will help to fray the edges more if you can wash it with some other items. Blue jeans are good if you have an old pair that will not bring the dye onto your curtain. Dry in dryer. (You will find a lot of thread in your washer & dryer as the edges fray.) Once it is all frayed you are ready to place the eyelets. The easiest way for me was to lay the plastic liner curtain on the floor and then lay my curtain over the top of it. Match holes from liner curtain to place your eyelets. Simple.
Here is a photo of my first rag quilt. To make the quilt you have to sandwich the squares with a smaller square of blanket and sew an X to keep them together. Then it's pretty much the same concept as the shower curtain without the eyelets.
top photo is the front side and bottom photo the ragged back side