Mesh......

Today's square was very quick and simple to make - but I don't think it'll keep you very warm when used in a blanket as it has lots of holes:

Pattern:
Create a foundation chain.
Treble crochet in the 8th chain from the hook, *two chains, skip two chains, treble crochet in next chain, repeat to end.
Chain five, *two chains, skip two chains, treble crochet in next chain, repeat to end.
Repeat second row until mesh is square.