My preferred trading situation is to trade up (I only rarely trade down), but I'll usually entertain anything of roughly equal value.  That being said, please don't offer me a slew of low-value cards that add up to the value of the higher-value cards I have on hand.

If you're looking for a specific edition and I don't have it listed, just let me know and I'll look it up.

For the most part, I trade for playing (as opposed to collection) purposes. I'll typically use envelopes with top-loaders; if you want additional packaging, let me know.  I'm happy to provide it, but I'll expect a little extra value out of the trade in order to cover the equivalent cost. 

There are a number of cards I have on my tradelist that I value more highly than their prevailing price would indicate (e.g. Stoneforge Mystic, Demonic Tutor, Vesuvan Doppelganger).  The reason they're on my trade list at all is for significant, high-value cards that I wouldn't be able to get virtually any other way and would only part with in a Godfather Offer (i.e. one I couldn't refuse).