Even if you're laying the tiles in a random pattern, it's important to line up the pile of the carpet. Having the pile all in the same direction will help the carpet look like one large piece of carpet instead of several small ones. To check the pile direction, simply flip over the tiles and look at the arrow on the underside. When the arrows point the same direction, so does the pile.
Always start with the longest, straightest wall in the room when laying carpet tiles. Slide the first tile up underneath the baseboards in one corner of the wall to dry-fit, them apply double-sided carpet tape to the corners of the tile and press it into place.
When laying carpet tiles in a large area or one with walls that aren't quite square, dry-fit all of the tiles before beginning and adjust the layout to the space. Then, come back and install the tiles.
Continue laying down carpet squares, making sure to line them up with the first square.
Cut carefully. When a tile needs to be cut, carefully measure and mark the dimensions on the back of the tile. Cut with a utility knife, using a framing square as a cutting guide for a straight edge.
Turn the cut edge of the tile to the outside when installing. Two factory-finished edges will make a cleaner seam than a factory edge and a cut edge.
This project also called for carpet tiles to climb up the wall. Instead of carpet tape, use contact cement to adhere the tiles to the wall. Spread the adhesive on the wall and on the back of the tile, let set until tacky and dry to the touch, then carefully line up and apply the tile. Be careful – contact cement adheres to itself instantly, so there's no opportunity to wiggle the tiles into place.