I know I am a hoarder at heart. Growing up with my mum who was down to her last pennies because Dad was FA definitely resulted in me keeping things "just in case."
However, I have improved and have had a few big clear outs.
I kept all of Dd's baby clothes unless stained or stretched or bobbly.
Bibs I've kept unless really badly stained. I've kept all the muslins as I figure they are just used to mop up sick anyway.
Dd2 is due in a few weeks and I've got the stuff out and been washing it all. MiL keeps nothing. New everything, every season, including gardening equipment. 
She says I should have thrown all this stuff and baby toys, gym, playmat and jumperoo, out and buy all new. She also makes the point that the baby will get presents so I don't need to keep all the old things.
I say, the stuff is expensive and perfectly usable again. Do people really not use things again for subsequent children?
I would rather wait and see what, if anything we get as gifts then take it from there.
I just hate the idea of throwing them out and spending a fortune again.
She also went mental when she discovered that I keep doubles of gifts dd receive and re-gift them. I put £10 in her bankie each time I re-gift something. Apparently they are all her toys and she should get them all. No child needs 3 of the same dolls, imo.
I am just not sure if I am right or if my background is making me keep things unnecessarily.