How should I expand my Imperial Guard army?

[Ulrik_Ironfist]

You want to have a solid core of infantry to be sure, but you don't want to overload yourself with it either. Lots of people play mechanized lists because it's faster, which given the objective heavy meta of 7th edition, is actually a good thing. I shudder at the thought of moving 150 infantry around on foot, because that's what you have to do with blobs. Even with artillery it sounds like you want your infantry to do most of the work, Which really lends itself to playing vets, as they're more versatile. 

[march10k]

The other thing is...if you make two platoon command squads and say six infantry squads...you've got choices...there's no WYSIWYG difference between infantry squads and veteran squads...plastic cadian flak armor actually looks like carapace to me...maybe that's because my guardsmen look like this:

They actually have flak jackets...unlike the new models that look like they're wearing carapace, just less of it

Anyway, six squads plus three command squads and you probably have all the infantry you'll ever use:

a) up to six vet squads

b) two platoons, with 20 men left over for either bigger platoons or a pair of vet squads to go along with

c) one 55 man platoon and a vet squad

You might eventually want more infantry, but once you've got 6x10+3x5, additional models get less and less useful. I would know...I have precisely 75 of my ~250 metal cadians repainted to my new paint scheme. The rest are a mix of "bought on ebay" in various states and about 50 more that still have my vintage 1998 paint job on them (it's bad...my first army, and a mix of testors enamels and citadel acylics)