Like any other project, the first step of building a great model is to plan. What color will you paint it? Which options will you include? Which version will you build? What other items – tools, paints or skills – do you need? This step will also include research. Although I had new about the F4F Hellcat, I needed to head to the local library to remind myself of the details, like the color of the plane and schemes. You might need to look up markings for your airplane or camouflage patterns for an AFV. You next need to examine your kit to answer the questions I asked above.
You might think that it's time to start building, but don't. One secret to a neat model is to do as much painting as possible while the parts are still attached to the trees. Wash the parts in mild dish soap and warm water first, being very careful not to lose any parts. As part of your planning process, you should also make note of any parts that can be combined into sub-assemblies before you begin painting. Often, fenders or engine parts should be glued together and the seams sanded smooth before painting. Look for and correct any defects in the model's surface, like mold lines or shrink marks. Add model putty as needed and sand smooth. Lightly sand all parts of smooth surfaces, like car bodies, with 600 wet sandpaper, in order to help the paint stick to the plastic. Be very careful not to sand off any details!
Now it's time to paint. Following the kit's instructions and your reference material, paint all the parts the correct colors. You can add a little bit of black to silver paint to make different shades; if you look at a real car you will see parts in several shades. Use spray paint whenever you need to cover a large area, like a fuselage, hull or body, and use your airbrush for camouflage patterns. You can also cut holes in cardboard and hold it about 1-2 inches away from the surface to create soft-edged camo patterns.
Now that everything is painted, it's time to begin assembling the kit. Use a cutter to remove the parts from the trees and then file the remnant smooth. Touch up the paint if required. Scrape away paint and chrome plating from the surfaces that will actually be glued together. Use liquid cement and take your time. Tape, rubber bands or clamps can be used to hold parts while the glue sets.
Additional tricks: You should lightly sand the surface of tires to remove the molding seam and to make the tires look used. Use 3M Fine Line masking tape to mask exactly along the color-separation line, then use regular masking tape to cover the other areas. Rub the tape edges with your fingernail to make it really stick; you don't want paint creeping under the edge. You can also use epoxy to hold clear parts without fogging or chrome parts without scraping off the chrome.
You have probably noticed by now that most of my tips are to paint and build carefully. If you take your time and work carefully, you can build models that you will be proud to show off.