You need to know the size of the cards when they are finished, that's 2 dimentions that you will have to accurately cut for every card. Know those numbers before you start.

For cards with double sided printing, hold the cards up to a light source with the back of the card facing the light. See how much drift has occurred in the printing process so that you know where you need to be more careful when you cut.

Always cut the cards face up.

Do not assume that the edge of the paper is square with the printing! Your first cut should be to separate individual cards - judge the center of the white space by eye, take extra time, this first one is important!

When using rotary cutters or a knife blade cutter make sure you hold the entire length of the paper firmly to the cutting board, as you cut, it will tend to drift into the blade. Do not attempt to stack multiple sheets for one cut! You will have a great deal of drift if you do this. Laminated cards are slippery, especially when stacked.

After you have one good cut, use that cut as your straight edge to make the rest of the cuts from, and be sure to use the straight edge and ruler on the cutting board. It helps to use a square also, and don't be afraid to tape it to the board so all the cuts are the same..

Take one of the strips, and cut one of the cards free from it using the straight edge of the cutter and your eye to pick the center line between the cards.

The cards should have 3 straight edges by now and all you have to do is make the last cut for each card. Reposition the square and tape it down to the new dimention. Cut the rest of the cards. See how bold we've become? The photo shows that we don't use the boards straight edge (don't try this your self, you might be unhappy with the result)