Assembling a comfortghan (comfort+afghan..clever, no?) is very rewarding and consists of several challenges.
First: One must collect enough squares to make the afghan the right size. Collecting the squares can be quite easy if you are in an established system like
Heartmade Blessings. It also can be quite difficult if you are sending out spamesque emails begging your Internet friends to help. Either way you have to come up with the correct number of squares in time to still comfort the recipient. "Hi, remember when you were sick two years ago? Here's a comfortghan to help make you feel better now."
Second: The squares need to look attractive once together. This can be quite a challenge when someone interprets your request for "happy" colors to mean safety orange & lime green. One hopes the finished ghan will comfort the recipient, not cause seizures.
Third: The squares have to be more or less the same size before assembling. I lean toward using 12 squares that are 12 inches each. If a square arrives that is 14 inches (and one hopes that it is square, but that's not guaranteed) it's easy enough to rip out a row. Likewise if the square is 10 inches it's easy to add a row or two.
Fourth: Arranging the squares so that there is balance and harmony. One of the neatest aspects of a ghan made with squares from 12 different crochetiers is that you see each persons style and taste represented. Laying out the squares on the floor and arranging and rearranging them is probably the funnest part for me. I do the trick I learned in art school where you squint at the ghan which essentially eliminates the color and allows you to see the intensity of each square. I then arrange them so that the most intense squares create a pattern such as a zig zag, or an X, or four corners, etc. It's an easy trick and creates a sense of balance, which hopefully leads to comfort for the recipient.
Fifth: The yarn that you use to join the squares together, along with the joining method can make or break the final ghan. After I've decided the arrangement of the squares I look for a color that is hopefully represented in a majority of the squares. If there isn't one I will go with a contrasting color that will visually unite the squares. Then I choose a joining method based on what type of squares I have received. If I receive mostly "flowery" squares I will join using pretty frilly stitches that will make the ghan as feminine as possible. If the squares are manly then I will join using stitches that create a tailored geometric feel to the ghan.
Sixth: The cat.