There is nothing like a handmade knit blanket. Thick and cosy, handmade knit blankets quickly turn into treasured heirlooms. Knitting a blanket is really no different than knitting a washcloth or scarf; except they are much bigger. While knitting needles can be long enough to accommodate enough stitches to make a baby blanket, knitting a blanket with all the stitches smooshed onto your needles is difficult. You can't see where you are at in your work, or keep an even tension, and it is easy to drop stitches. Instead, knit a large blanket on 40-inch or more circular needles, treating each end as though it were a separate needle. Another option is to make panels and seam them together.
In order to make a large knit blanket with a continuous pattern, you will need to use a circular needle. The long connector allows you more than ample room for your stitches. Use the circular needle length that best suits your work. For example, use a 60-inch circular needle if you are making a very wide blanket.
Cast on to your circular needle just like you would normal straight needles.
Knit your work back and forth in pattern, treating each end as though it were a separate needle and turning your work at each row.
If you don't have circular needles or you would rather make a pieced blanket, use straight needles. You can piece together long panels, squares or shaped pieces. In any case, varying the colours of the pieces used will create different effects. For example, you could use square or shaped pieces (and a little inspiration from the quilting world), to knit a large blanket that resembles a patchwork quilt.
Knit your pieces as the pattern calls for, or, if you are making your own pattern, knit enough panels to the length you desire to create the width you want once they are sewn together. For instance, if you want a 45-inch by 60-inch blanket, you will need three panels that are 15 inches by 60 inches. Alternatively, if you are using knit squares or pieces for your blanket, knit enough to make the size you want. For example, if you want a 45-inch by 60-inch blanket, you would knit 12 15-inch squares.
Seam together your pieces. This could be done through using a yarn needle and yarn or by crocheting the pieces together.
The method you use to piece your sections together for a pieced blanket will change the look considerably. Use a pieced blanket as a way to showcase different stitch patterns.
A blanket's pieces get heavier the longer they get. Using a circular needle to knit large flat pieces will reduce the weight. Consider using a circular needle even if you are making a pieced blanket to make the blanket's weight less cumbersome.