I'm using the below method to paint pikemen in groups of 12 or 16 for my big pike project. Although there are a lot of steps, each one is pretty quick and I can finish a batch in around a week. I've tried to rationalise the process and include lots of shortcuts such as Army Painter and the use of spray primers and varnishes.
Stages in the Mass Phalangite Paintjob
1. Spray prime minis brown (I’m using Montana Gold “Palish Brown”)
2. Paint linothorax and sword hilt white
3. Block in tunic and plumes in various colours; highlight
4. Paint coloured trims on some linothorax
5. Block in flesh tone, then highlight
6. Paint leather straps brown, and retouch brown around tops of boots, base and back of shield
7. Highlight leather straps
8. Paint hair black or brown, highlight
9. Paint helmet cheek guards black
10. Drybrush base in earth brown.
11. Apply army painter “soft tone” dip (except over shields)
12. 1 coat gloss spray varnish
13. 1 coat matt spray varnish
14. Paint shield facing, helmet, greaves, cheekguards Vallejo brass
15. Highlight with brass mixed with a hint of silver
16. Apply army painter “strong tone” to shield and helmet
17. Spray paint pikes “Desert Yellow”
18. 1 coat gloss spray varnish on pikes
19. 1 coat matt spray varnish on pikes
20. Paint pike heads black, then dark silver and highlight.
21. Attach pike; retouch
The sample figures at the top are at different stages; the first is at stage 3, the second is at stage 16 (I just need to paint the cheekguards on his helmet). The third is finished, except that I need to matt varnish him as I skipped the spray matt stage. Bronze-faced shields are the easiest thing in the world to paint!