Some notes on trading:

I look for comparable TCG mid values, and I will usually also compare the actual purchase price of those cards on TCGplayer.com in case there is a significant discrepancy.

I would like to keep trades to $15+ if possible.  I ship cards in bubble mailers, with cardboard on both sides, and with tracking.  The more valuable cards ($5+) will definitely be in toploaders, but all cards will be adequately protected from damage. 

If I have multiple trades out involving the same cards, the first trade accepted will get those cards, and the other trade(s) will be modified or cancelled.