With three grandchildren on the way, I need to have a few baby blankets in store, so I made this one out of left-over and hand-me-down baby weight yarn. Here's what I did:
Step 1: Gather all yarn of similar weight. It doesn't have to be exact. You will be guessing at the amounts, but you should have a total of 16 - 18 ounces of yarn. Using a kitchen scale if needed, divide every yarn color and type into two equal piles. Put one pile in a bag and set aside.
Step 2: Choose a color from the pile not set aside. Using size 6 needles, CO 200 stitches. Work in double seed stitch pattern for approximately 12 rows. (If you have less yarn, CO fewer stitches for a smaller afghan.)
Step 3: Switch to a new color. Work 6 stitches double seed stitch. Knit across to last 6 stitches if your change is on the right side of work. Purl across if your change is on the back side. Work the last 6 stitches in double seed stitch. On the next row, work 6 stitches double seed stitch. Then choose a new pattern and knit across to last 6 stitches. Work 6 st double seed stitch. Continue with the new pattern for as long as you like, keeping your double seed stitch edging. Try not to use all your color up in one stripe.
Step 4: Repeat step 3 as many times as needed, changing the pattern stitch every time you change colors, and changing colors as often as you like, depending on how many you have.
Step 5: When you have used up your first pile of yarn, or your afghan is about half as long as you want it to be, get out the pile of yarn that was set aside. Match your color sequence going backwards. Don't match the patterns unless you want to. I didn't -- except the last color which is done in double seed stitch like the first.
Step 6: Bind Off.
Step 7: (The least fun one) Sew in all the yarn ends.
Double Seed Stitch:Row 1: K2, P2 across.
Row 2: K the knits and P the purls.
Row 3: P2, K2 across.
Row 4: K the knits and P the purls.
NOTE: Avoid rib and cable patterns as they will have a smocking effect.
You won't have the exact number of stitches for most of your patterns. When that happens, decide whether you want to stop in the middle of a pattern when you get to the end of the row or you want to have a few extra knit stitches on one or both ends. You may do it one way with some patterns and the other way with others.
I used the following books for patterns to sample:
Donna Kooler's Encyclopedia of Knitting
Sampler Afghans, Leisure Arts Pamphlet #932