laundry tips for baby clothes

Hi! I need some tips on how washing & storing baby clothes.

A couple of months back I took out some baby clothes from the bags they
were stored in and noticed that some of them were covered in yellow
stains.

It looks like it's from the baby spitting up, though my older son didn't
spit up all as a baby. In any case, I did wash the clothes thoroughly
before I put it away.

Now I want to store the clothes away again. This baby, though, spits up
literally non-stop and I'm worried about how the baby clothes are going
to look like in another year or two.

How should I clean and store them to prevent them staining? I'm from
England, so names of any UK detergents would be useful.

Thanks.
--
Zippy S