boost and vet them or just vet and expert them and you will do fine against the same or lower lvls

At low and medium lvl boosts experts and vets matter more than the base. A base +9 full bve will beat an elite no-bve, be sure of that.

At high level (if pilots are good bve) base doesn't matter at all.

How do I boost experts / veterans?

those are ($$) items from the NF stores 

During events troughout the year they also give those items away for free during normal gameplay, so you can gather them by playing during events. (except for this one, its only extra xp atm).

if you play cv remember to use all your items on your fighters, bombers will reach AAW immunity (max performance) easily without the use of items.

Keep in mind, unless you can afford to keep the experts and veterans at max you should be classing them as soon as the next class comes available (especially for the fighters). Many people will advise others to class them late but not explain why, therefore confusing the living hell out of people. The trick to late classing it to keep the experts and vets up, which can be quite expensive. Unless you happen to play during item drop events ^^

Get Elite fighters.  Min +12 fighter 10 air if you absolutly cant pay for elites.  You will get hammerd without elite fighters.  Bombers are ok just get +12 bomb 10 air.

Use nothing that has +11 stats.  Only use +12 saliors !!!! roll all night if u have too.

Do not use The yellow colored saliors nf gives you. Roll you own.

use a +15 potential for your B.O, aka captian.

Do not make torpedo saliors ever there usless unless your a sub or a kita.

Picking a cv is a good start before you do a bb. But you should do U.S as your 1st nation not km Get elite accuracy gunners.  nf tell lies in the info about nations.

Im telln u bro get all +12's or elites dont listen to these guys and 11/11 garbo. 

When you trade and sell them ppl pay way way more.  why? there way better.

start with the best crew u can get it will pay off.  No 11's !!

Elite will always beat normal ones.
Elite+boosted+full vet will be the best fp setup, tho for bomber it doesnt really matter that much.