In 2004 at my workplace, crafters started to make crocheted and knitted blankets for our local chapter of Project Linus. This is one of the patterns I came up with.
It's a very, very basic granny square blanket. The nice thing about grannies is that you can use whatever yarns you have on hand, as long as they're similar in weight. You need to reserve enough of one particular colour to join the squares together, then go around the whole thing once or twice, you're all set.
For this particular blanket, a coworker whose creative talents lie elsewhere, noticed a bag of yarn at a yard sale. She asked her Mom if this would be suitable for making a little blanket for a child. Mom said "yes" as it was all acrylic worsted, so she purchased the bag of yarn. The next workday, she handed it over to me, as she knew I was making blankets for this project. Thanks LW!
Make 30 squares in assorted colours. Reserve at least 50g (1 3/4 oz) of a single colour for joining the squares together and making the edging (a particularly dark, bright, or light colour works well).
Arrange the squares in a pattern or randomly on a flat surface. (Ironically, the most difficult part of making this blanket can be trying to make the arrangement of squares look random!)
Once you've decided on your layout of colours, determine a short form for each colour in your blanket. I used hp for hot pink, r for rose, dgr for dark green, m for mint, etc. Grab a piece of paper and pen and write down where each colour square goes, something like this:
hp dgr r m r dgr hp dgr m...and so on. This little chart will come in extremely handy once you start joining them together, especially if you have to put your work away before you're finished!
Join the squares together using your favourite method. I like to join two whole rows (or columns) of squares together, from the wrong side, using single crochet, with one long piece of yarn (fewer ends to work in later). In other words, join all horizontal (or vertical) seams first. The squares won't be joined in the other direction, so it will look like a blanket with a lot of slots in it (between the squares). Then I work all seams in the other direction, from one edge of the blanket to the other, again using one long piece of yarn per seam.
For the edging, I worked a hdc in each st all the way around, working 2 hdc's in every corner. Then I worked a second round of the same. I didn't work a hdc into the ends of the seams. You could add a third round if you like, stick with one round, or use a different st, etc.