Tons of physical and mental rest (gauge how much you think you need, then add even more)

Good nutrition every day (at every meal if possible)

Lots of water

Supplements: fish oil from reputable manufacturer (possibly in a high dose), good multivitamin (with strong B component), vitamin D3

Dark, quiet room to recover in

Minimal stimulation (TV, reading, internet, email, conversations, noise, chaotic environment, etc)

Large support network (family, friends, knowledgable health professionals), to the extent this is feasible - ask for help if others are receptive and willing to provide it

Light activity / exercise only if it doesn't trigger symptoms

Don't skip meals

Practice meditation or listen to music - or find some other way to relax and de-stress, even for 5-10 mins at a time

Minimize stress, to the extent this is possible

Take lots of naps, even short non-sleeping ones

Read relevant sections in Brainlash, Coping with Mild Traumatic Brain Injury, Mindstorms, or other credible sources for additional knowledge and support

Patience