...gently suggest that if people are going to buy clothes that they buy something other than 0-3 months. I'll never do it because it's way tacky, but seriously I'll have to change the kid 3 times a day for the first three months if I have any hope of him wearing everything that we've gotten in that size. And the big family shower isn't for another three weeks.
Don't suggest this unless people come to you and specifically ask what you need. If you wind up with too many clothes in a certain size, go exchange the ones with tags and receipts for larger sizes.
I think a lot of people realize this, and buy a variety of sizes. At least they did at my shower, and with any other gifts we received. After sorting all of her clothing, I realized I didn't have a single thing that was 0-3 months...yet her closet and drawers were full! Which is totally fine of course. I just found it funny looking at how much clothing she had...and yet I had to go shopping so she could have something to wear when she arrives.
You may be surprised to find people buy clothes in larger sizes. I only got two NB outfits and the few other clothes I got were 12 months and 18 months. Many women think about that when buying baby clothes.
Re: I wish I could...
How do you know where things came from? Or do a lot of stores carry the same basic things?
Also a lot of people will give you a gift receipt with their gift now a days