I haven't thought of that yet...I've only just discovered who my EM is (it's Jennifer O'Leary...anyone got any great things to say about her?). I'm anxious to begin working with her. If things work out well, I don't think it would be inappropriate to give some token of appreciation. Especially if your EM does something extra special somehow...
I haven't decided on my officiant yet. I know that for "regular" weddings, it's customary to give a "donation" to the officiant in addition to his regular fee. Though, in this case I'm just not sure. I'm not sure what I would give an officiant...
We gave both our EM and officient gifts. We actually went to WDW a few months prior to the wedding to meet with our EM and officient, but our EM was out of town. We gave them both a basket full of Louisiana treats that time around (left hers at Franck's). Before the wedding, we gave our EM a gift basket from Bath and Body Works and our officient a ceramic cross that had purple and gold beading on it, in recognition of our wedding colors.