Is there anything we should be doing to reduce one of our girls spewing all the time?

Whether she is on the breast, bottle EBM or formula, it's usually the same story. She feeds for a bit, then spills a bit, feeds again, spills a bit more and so on. Once she is put down, she often brings a lot back up, but is never upset about it and doesn't seem uncomfortable.

When she is on the bottle we gently burp her regularly. One thing I have noticed in comparison to her sister is that she sucks quite aggressively, and it can be hard when she is on the bottle to get her in a position where she isn't sending little bubbles of air into the bottle. This make me think that as a result of her sucking action, she is introducing air into her stomach as well?

This is a very similar question to human bean's thread - but I wasn't sure if it was the same thing and didn't want to hijack.

Thanks peeps.