Film coverings today are great if handled according to the instructions. (Most manufacturers include instructions in every roll.) Just take your time, use the right heat settings, use a "sock" on your covering iron to avoid scratches, and remember to use the covering's properties...

What I mean by that is that most film coverings will go around even the weirdest curves, if you just heat it a bit with your heat gun, and stretch it with your (gloved) hand around the curve. (like a wingtip) Heated, these films stretch quite a bit. Don't depend on heat alone to shrink the covering, but rather, put a little tension on it when you tack it down. Later, when you come back and shrink it, it will be tight.

If you can't avoid getting a bubble in your covering, which often will happen in the "covering over covering" situation, just take a small pin and puncture the bubble, releasing the gas, and shrink the covering. Use a very light pressure with your covering iron, so that the heat does most of the work, and NEVER just rub the covering back and forth... You're asking for a "smear" of wrinkles!

Anyway, the pin hole won't be visible, and it won't have any structural effect. To avoid bubbles, make your covering overlaps as small as possible. Very few "pro" finishers will, for example, cover a wing with a solid color, and then start applying a complex colored pattern over it. It's much better (and lighter!) to plan your covering scheme in advance, and try and keep your covering "one layer", as much as possible.

And, paraphrasing an old Jeff Troy (AMA) videotape, "The way to avoid having a visible seam is to not HAVE a seam. Make it a color change instead." So, try and plan your covering scheme mentally before you start sticking film to the plane. Make a sketch, and maybe even cut some precise patterns in advance. When the color changes from say, red to orange, you don't think "seam"... You see the color pattern. Change blades often in your hobby knife. Using sharp blades all the time will greatly improve your results.

One final "old timer" observation. Don't be too impressed by what you see in photos. It's the nature of both film and digital photography that generally, the finish on our models can look a lot better in the image than in real life. Photograph your own work and you'll see what I mean.

Model Airplane News has several great books on covering. (Faye Stiley!)