Allow yourself lots of time to get the alignment right. Keep printing drafts on plain paper, holding it up to the light with the card stock behind it to make sure you have the text where you want it and the color you chose looks nice, before printing, so you don't waste any cards.

I have found that it is MUCH easier if you choose a card with a border that is even all the way around, especially if you chose one that has two or four to a card. You will save a lot of time on getting the alignment right if you aren't trying to figure out how to avoid a picture in one corner or a flower that sticks out here and there.

Have fun.