I don't use it very much except to sell my bitcoins at regular intervals for expenses. The only advice I would say is to only fill the online buy orders because of the escrow, where you only release bitcoins after the buyer has paid (in my case I use online bank transfer). I may get about 2-3% less than other offers but I would never make a trade that doesn't use escrow. I recommend that as minimum to prevent being scammed.

I would assume the same for posting sell/buy orders. There are fees involved, but as you'll find on LBC, the fees are priced in anyway, so you're still likely to make more than when using non P2P exchangers.