Consider scale before you choose a model. Some people like to stick to one scale so it’s easy to see the relative size of the subjects. It is exciting to see how a Douglas DC-3 is dwarfed by a Boeing 747 and reflect on aviation in the 20th century. Others like to mix it up and build a variety of scales and subjects.
Your choice of scale depends on what you want to build, how you will display it, and how many and what sort of models you want in your collection. If you live in a house with enough space for a dedicated hobby lair, your choices are obviously different from a cozy apartment in midtown Manhattan.
Here are some of the things various scales offer:
Large scales (1/4 scale to 1/25 scale): This is, well, largely the domain of autos, motorcycles, and figures. One of these models can make an impressive desktop display; two or three of them and you’ll be looking for a bigger desk. Most car models are in 1/24 or 1/25 scale, and several of them can fit nicely on a bookshelf. But a P-51 Mustang in 1/24 scale? With an 18½" wingspan, you’ll soon need more shelves.
Many figure modelers enjoy large scales (1/8 or 1/12) for the opportunities they present to give the figure authentic and accurate details such as bootlaces, equipment webbing, etc.
Midrange (1/32 to 1/48 scale): Traditionally, many military miniature figures have been sculpted in 1/32 scale (also referred to as 54mm). These are often used with 1/35 scale military vehicles, which are close enough to match up. And 1/35 scale is the most popular for armored fighting vehicles (tanks, halftracks, self-propelled guns, etc.)
Recently, 1/32 scale aircraft have been increasing in popularity. Again, this is a great detailing opportunity — but you need a lot of space. A B-17 Flying Fortress in 1/32 scale has a 40" wingspan!
On the other hand, 1/48 scale is popular for WWII aircraft, especially fighters — large enough to build detail in the cockpit, but small enough to collect quite a few before ordering that next bookcase.
Small scales (1/72 to 1/200 scale): A lot of aircraft modelers like 1/72 scale for the variety that can be practically collected — some bombers and jumbo jets can get a bit unwieldy, but fighter planes fit in the palm of your hand. If you’re familiar with HO scale railroads (1/87 scale), you know just how small vehicles can be. Adding a lot of detail may require magnifying glasses. In fact, many armor modelers enjoy the challenge of building in 1/76 scale, where assembling tank treads and road wheels requires a jeweler’s touch. Compared to WWII warbirds, modern jetliners are massive enough to rate 1/144 scale. This is the most popular scale for airliners, although some are made in 1/200 scale as well.
Ships, not boats (1/200 to 1/700 scale): A rule of thumb: The difference between a boat and a ship is that a boat can be put aboard a ship. However, a ship cannot be placed on a boat. Thus, while submarines and PT boats may appear in 1/72 and even 1/35 scale, most ships are in smaller scales. Even in 1/200 scale a battleship will take the lion’s share of most kitchen tables, as will a 1/350 scale aircraft carrier. But 1/350 scale is the most popular ship scale, yielding shelf-friendly destroyers and cruisers. And, like 1/76 scale armor, 1/700 scale ships offer the challenge of micromodeling. In that scale, unassembled antiaircraft guns look like iron filings.