‘Blocking’ most simply put,  means saturating the blanket, and then allowing it to dry in the shape you want it.  It’s amazing the difference this will make to your project.  The reason is the wetting allows the yarn to relax, allowing it to settle into the required shape as it dries.

What you will need: laundry trough of nice warm water, some large bath towels to remove excess moisture, large towel or old quilt large enough to lay your blanket out single thickness for drying, tape measure, pins

This is the process, for large and small items alike, all yarns.

1. immerse the blanket in a laundry trough of warm water, comfortable to the touch.  If it is a fairly large blanket, fold it a couple of times, say into 4, to make it easy to manage by hand.
2. squish the blanket gently by hand, to make sure it becomes wet through, especially if it is large and folded.
3. when completely saturated, remove the plug and allow the water to drain out. When tub is drained, push by hand until more excess water is squeezed out.
4. to avoid distortion, gently lift the blanket out of the trough, and lay on towel roughly in shape, then roll up towel like a jam roll, then gently press down again, to remove excess moisture.
5. repeat step 4 if necessary – you will find blanket becomes much more manageable once most of the moisture is gone.
6. have your drying surface ready.  I use a big old cotton quilt laid out on the floor of the living room, or even on a shaded back patio.
7. gently lay the blanket out, unfolding  if you have folded it to saturate, into a single layer.  as you do this, start by lining up one top edge and one side edge of your blanket, with a top and side edge of your drying surface, so you get your first right angle corner set up.  Use pins if you need to keep in place, this is easy if you have put your drying surface on carpet, for example.
8. gently spread the blanket over the drying surface quilt or whatever, laying it out into the shape that you want.  Do one top edge and one side edge first, then the other side and top edge.
9. use the tape measure to check that your top and side edge measurements coincide, whether the blanket is a square or rectangle.  Use pins where required to hold in, or ease out areas of the blanket that need some extra help to settle in.
10. please know that this will not necessarily create a perfect shape, but will make a big difference to your project!  And I am sure it will be just as loved by the recipient!
11. IMPORTANT!!! It is important to know, that blocking is NOT permanent.  After blocking the blanket should always be dried in shape.  However it is possible to wash the blanket on a very delicate machine cycle, and dry in shape once again

Here’s another take from Little Birdie Secrets