When I started doing yoga last September I bought the cheapest fitness mat I could find. It was a foam mat. My yoga teacher told me it was better for the likes of pilates as it wasn't a proper yoga mat. When I eventually got a proper yoga mat the fitness mat ended up idle in the wardrobe.
I had an idea in my head for a few weeks but never got around to it until now. I measured the length and width of the mat and marked out 5 sections long by 4 sections wide and cut the segments. I was going to stack them all together but found that might be a bit too high. So I divided them into 2 piles. Maybe slightly flatter than intended but when I get more flexible they'll be just right I'd say.
I wrapped them in duct tape and now I have 2 homemade yoga blocks.
They'll come in handy for sitting in a cross legs position, sitting with the soles of the feet together & knees out wide position, and, practising jumping from downward facing dog to feet between the hands - which we've done in yoga class before. Indeed anything where a block is needed in my practice.
I can't quite get my legs low enough to the ground in a cross-legged sitting position due to a lack of flexibility in the lower back and tightness in the hips (and possibly anterior pelvic tilt) so the block will help me sit with better posture without too much pressure on the lower back and hips.
Like my younger brother says: "the ideas are there, only to think of 'em."