Design & Modelling - Bases
Pretty much every wargame with figures needs those figures to be based. With some games like Test of Honour which are a structured product line, these are supplied and a set standard. With more wargaming, the ruleset is often agostic on this point. This decision is more complex if you plan to use the same figures for different games (or want to leave the door open to doing so).

This is an issue because really the footprint on the table is what's important. This was brought home to me recent when I saw a demo game of Warlord Games Black Powder at a convention. They were playing with 54mm figures (i.e. double size), but hadn't changed the scale - they simply had less figures, making the footprint of the unit the same. Great for a big demo, even if it did make their battle look more like a skirmish wargame

From a game design persective, ground scale is actually tied to unit sizes (if you care about scale, which some games don't). A regiment of 600 men has a known (by experts) frontage. If you represent that with 12 figures (one figure = 50 men) you can measure the frontage and that determines the ground scale. That then gives you firing ranges, and when combined with the time scale (how long is a turn?) gives you the movement rate.   

When deciding what bases to use for games that give a choice, there are a few points to consider:

- round or square. Games with individual figures (generally, one figure = one person skirmish games) often look better on round bases. However, square bases can easily to put together to form a 'block' unit for a game that needs that.

- individual or mutibase - figures can be glued together ona bigger base. This makes movement easier,  allows them to be less static (overlapping it's other's space)and allows for more base decoration. The drawback is it makes them less flexible to use / split up.

- size. For 28mm piecess, the smallest practical option is 20mm (that's side length square or diameter for round) bases. This happens to be same size as UK pennies, which some people literally use as bases - they are cheap, easy to get, heavy, and the newer pennies respond to magnets so will be held in place in a magnet storage system. I've also seen multibases which take pennies - you put your penny base into a wood piece with holes to fit, turning them into a block unit. A bigger option is 25mm (as used in Test of Honour), which personally think looks better. I've haven't seem them used locally but I'm aware they are multibases to turn these into a block unit - but a much wider one that you would otherwise get.

My current approach to basing:

- My Battletech figures are on plastic hex bases, to fit the hexes on the standard boards (the game can also be played on terrain - more on that another time).

- My Pike & Shotte figures are stuck on multibases, 4 figure 40mm squares for infantry, and 50mm squares for two cavalry. I use 25mm * 50mm for the mounted commanders. The ruleset is also open on unit size and I go for the smallest end of the standard size range, to get the most out of the figures. 

- For Test of Honour I use the standard bases supplied. It also includes some big circle multibases (takes 3 figures)

- I'm still thinking this point over for Saga which is a ruleset, rather than a product line so allows a range of options. I'm tempted to use 25mm round bases to match my test of honour figures in case i ever use them together (Samurai rules for Saga are planned in the future); I could also reuse the same multi-bases I've already got. The alternative is to use 20mm pennies, since those fit better onto a multbase in case I ever want to play a block unit game with them. Naturally I want to stay consistent once I decide on this.