I usually go for peaceful diplomacy.
By allocating dormant outposts between my neighbors and myself, I can usually get one more than the average number of close outposts (so in a ten player game, I get 6 dormant outposts instead of 5).
Then, I get a speed or defensive specialist and get together an early mine, but wait long enough so that I am the second person to do so to avoid immediate aggression.
Managing peace deals through the promise of funding also helps keep your border safe. Be careful though as having many allies means that 1) they may not be as trustworthy and/or 2) it will be harder for you to expand.
Oh yeah, and communication is key! Keep in check with your neighbors and discuss other players, or share strats to increase trust. Even sharing life stories can increase friendships.
Reporting from the Bridge