Macarons - help please

[PerspicaciaTick]

I made two batches of macarons today.
The first lot spread and I ended up with large, very thin discs.
The second lot rose a little, but the beautiful glossy tops lifted off in a paper thin sheet, leaving the chewy bit on the baking paper.

They all tasted lovely, but what am I doing wrong?

Is it a question of leaving them to rest for long enough before baking them?

The other thing might be the size of the eggs you're using. If they're spreading, it could be that the mix is too liquid because the egg whites are too large.

Some recipes I've seen specify a weight of egg white, not just the whites from, say, 2 or 3 eggs.

Thanks tb, you are right, the second mix was firmer...and I may have rushed the waiting a little. Is it OK to leave them to sit for longer than 30mins, or does leaving too long cause other problems?

Think it should be ok to leave them a little longer, can't remember if I've done it for a strict 30 mins in the past - been a while since I made them.