PE for ship models is usually small pieces - a 6" steel ruler (to hold the piece along the fold line) and a razor blade (to slip under the part and fold upwards) will work for most larger pieces. Small needle-nose pliers will work for smaller pieces. I have a folding devise and rarely use it. You can get a variety of aluminum oxide sandpaper (the gray stuff) in fine grades at DIY stores. When putty-ing small spaces and cracks, I prefer Squadron White Putty. You can thin it with Tamiya Thin cement - I find it bonds better with plastic and is more durable when hardened. Sands well and holds paint no problem. Since I airbrush, I use Tamiya acrylics thinned with their lacquer thinner exclusively. For a protective clear-coat I use Tamiya Flat Base mixed with Future floor wax mixed roughly 25 - 75. Mixture can vary according to how flat or semi-flat you want your finish. (A satiny finish is easier to keep clean than a dead flat finish, as the flatter the finish the easier it is to hold dirt, dust, etc.). You can cut costs by economizing on tools, but don't buy cheap ones - they'll break or wear out faster! You'll learn better what works and what doesn't through experience.