Invest in Training Pods and Pilots early on. Your pilots will be inevitably injured. If you have pilots with high enough guts, they will survive sometimes but will be out of commision for 60-90 days at worst. If you need a reserve pilot, they should have Bulwark at the least. Training Pods will give enough experience to get at least 2 of the Basic Skills without needing to take them out in missions. You should at least hire 4 spare pilots and only use the XP to level their skills when the need arises.

When negotiating, always get 3 Priority Salvage slots. Meeting a King Crab or Atlas with max Cbills and no Priority Salvage is the most frustrating thing you can experience.

Keep spare mechs mission ready if you can. Preferably Mediums. Mediums are still viable at 4 Skull missions and can be used to supplement your lance if you find your some of your Heavier mechs under repair. Another thing is that Escort missions will most likely need mechs with significant sprint distance to keep up, you will need 1-2 mechs to get ahead to draw fire and keep the enemy from focusing the escortee.