Step 2: Trimming & Assembling (Main Card)
If you printed the card out on two separate pieces of paper you'll need to attach the outside and inside to be one complete piece. Start off by flipping one of the pieces of paper over (noting where the edge of printing ends). Place a boarder of double sided tape around the edge of the entire side, then one single strip down the middle, where the card will fold in half.
Keep in mind not to place the tape where it will get entirely trimmed off.
Now we need to align the two pieces of paper. Be sure the front and back are both flipped the right directions, so the inside of the card isn't upside down.
Once you have the two pieces together, bust out the X-Acto knife and Ruler, and trim off the remaining white boarders around the outside of the card. If you're worried about the card not being aligned correctly after taping it, there's a pretty decent margin of error where you can cut into the colored print, and it wont be too noticeable.