i have tried using a template to make decorative wrappers but have a problem getting a finished uniform edge.
when i join the two ends together, there is a dip in the wrapper rather than a continuous edge.
any suggestions would be much appreciated!

Does it have a tab where it joins? It might be that the wrapper you're making is too tight on your cupcake, or too loose.

Where did you get the template? Did you draw it yourself? PM me your email address and I'll send you one I have so that you can print it out and see if that one fits. Or you could compare the measurements to the one you have and see what the problem is.