Answer:
warm your tortilla before you start rolling everything together. Just for 10 seconds on each side in a pan, or quickly in the microwave, you'll be surprised how well your wrap stays together
and make sure to wrap it like this
Fold the sides of the wrap halfway towards the center
Bring the bottom third towards the center
Tuck your filling back into the wrap as you roll it up
Continue folding the wrap from the bottom until you reach the end
A dab of a smear of your choice on the edges to keep the wrap together