Hi Ken, I keep 100' of sash cord on hand at all times - I love the stuff. With a few well placed loops you can get good pressure against the strips anywhere you want - without clamps. Sash cord is cheap and available at any hardware store. This picture describes my process pretty well. The top strip is a scrap; I can't remember why I used it here but it's not required. I have another picture on my site that shows the whole boat tied up. I ended up looping the rope tightly where the strip meets a form and less tight once in between each form. It worked great.

I started out using "U" clamps too but got tired of screwing them in/out. I hated the idea of hot melt glue the first time I heard of it but... you need something to keep the lower strips in place; they tend to bow out away from the forms when you clamp down on the above strips. Hot melt eliminates this problem completely and I use it often now.

Note, get gloves - the dried glue in the rope cuts your fingers.