I was recently reading an article about clutter causing stress and it definitely is in our place for both DH and I.

How do I learn to be ruthless and throw out stuff that has meaning to us? The thought of Christmas is already stressing me out about how to store the gifts the girls get and telling people not to buy them s--t that we simply can't fit into our home and keep it orderly also. Arrr I already have 5 garbage bags for Vinnies just from today but it feels like it has not even dinted the stuff we have. We have a very large home and every where I look there is just more stuff to go through. I want a place for everything and right now I don't have that.
I think there has been alot of good advice about getting rid of stuff - but the not wanting it in the first place is also a valid strategy.

We live in a two bed flat, the four of us plus occasional UK visitors for weeks at a time - space is at an absolute premium, but I wouldn't change my stance if I had a bigger place (although I do think people maybe respect my wishes because of where we live). I have no qualms about telling people not to buy us things - sometimes it works, sometimes it doesn't (birthday parties have a 50% success rate - but that is 50% less stuff). The world is full of stuff, I do not want people buying stuff for us just for the sake of giving us something, that I then either have to store or donate - I really think it is unfair when people say "but you are taking away my joy of giving" - for one if the receiver doesn't want it, how can that give you joy, two you can give gifts that are not things (experiences, memberships, days out, etc. food) things that don't take up any space at all, and three the joy that some people get from shopping is not the same as the joy of giving.

Anyway what I have found works, is making sure give people suggestions on the alternatives, experiences etc - also make sure give feedback about how much enjoyed things, photos etc. Talking about how much DD enjoyed special cinema trip with her uncle, all the stuff we do with zoo pass, museum pass etc etc. Just being honest about why you don't want more stuff (space issues, and environmental reasons in my case). Thinking about how can add something to another thing already have or getting, e.g. a bell or basket to add to a bike already getting. Not buying other people presents (birthday parties we do buy gifts unless invite states no gifts, as that seems to be the default position) but getting them 'experiences' etc. or money if that is what they want.