Prompted by a request by DeeRoc in the Viper Family thread, here's a quick "How To" apply model aircraft Heat Shrink film in rocketry applications in video format. Most commonly, you find Monokote (Top Flite) and Ultracote (Hangar 9); both work well though apply and shrink a bit differently...
I did it once a long time ago. Movers lost a box with about $100 of monocote in it 2 moves ago. NC's are a pain fins aren't too bad. The rocket met a bad end after a few flights (failed to eject and started a small fire). It's been so long that I don't remember the flight to much. Body tubes are pretty easy and fins not to bad. I've seen an adult sit on an well made monocoted wing in between two tables. So a built up fin could be made quite strong.
Warping can be a problem, especially with Balsa Fins. The use of Monokote, SolarFilm, Ultracote, and many other plastic model airplane-covering films have been used, at least since the 1970's.
This photo below is Martin Catt's ( DARS ) "Merlin" at NARAM-19, in 1977 ( Kansas City ) . . . He used Monokote on the Fins and as Trim.
The orange E Dual Egglofter to the right is mine, also at NARAM-19, powered by an FSI E60. Unfortunately, at that time FSI E60's were very cato-prone ( over 80% of them failed at NARAM-19 ) and the motor exploded, about 5 feet off the end of the rod.
I have covered a couple of mid and high power rockets with Super Monokote without issues. Might be because I have covered about a hundred balsa RC aircraft with Super Monokote and Ultracote over the years. One 3" airframe rocket model is 25 years old and still looks like new. No paint chipping.
While one poster indicated that the fin covering needed to be one piece with no seam on the fin leading edge, both of mine had seams on the fin leading edge. No issues in my experience. I did allow a generous seam overlap of 1/4" to 3/8" , though. Just be sure the overlaps are well sealed.
Have also used both Super Monokote and self adhesive Trim Monokote as trim on painted models.
Life is too short to cover nose cones with heat shrink covering, though....