Seems like they start with a foundation of some sort. I picked up white old fabric from a garage sale. Have enough to last a lifetime. But I hear them talking about using muslin, old newspaper, printer paper. You decide how big you want your block to be. 8" square is a common size, although a 10" , 12" , or a 15" could be used. My strips are all thrown into a strip box. The sizes of strips run 1", 1 1/2" to 2" . I would save my 2 1/2" strips for something larger, like a log cabin block. I do like the string blocks I see sewn from one corner to the opposite corner. It creates an angle. You might Google string quilt patterns or ideas. Most of them are free.