I am in a constant battle with myself :( I have 3 budiges in a big cage and they are very flighty. And I am afraid that one fine day when I am cleaning their cage one of them is going to take off

. So I am thinking about clipping them but my question is how do I go about it.
Heaven forbid I don't want to clip the wrong feathers or hurt them in any way is there anyone out there that can help me? May be a diagram ( I know that sounds stupid) I just want to do this right if I decide to do it.
Thanks