Favorite glue, the only glue that does the job for me anyway: Neutral pH Adhesive, archival quality by LINECO. It is "permanent, dries clear and remains flexible".
Could someone explain to me the paste and glue brush British way of collaging?
I don't understand what you mean by 'paste and glue British way'! (And I'm British.)
I must have used paste brushes in my British 1950s childhood, but in the 1960s was introduced to Cow Gum, which I fell in love with. That was always used with a plastic spatula-like thing, and I have smaller versions of those which I now use with liquid PVA.
However, I recently brought a tin of the Italian adhesive, 'Coccoina', and it has a small brush with it! I tried it - and went straight back to the small plastic spatula-like tool! Sorry ... 'adhesive spreader'!
An adhesive you don't have to be afraid of, and mini-spatulas? I'm there. ❥
I almost always use Pritt Stick, but for things larger than around A6 I use the 3M Spray Mount (repositional) though art course tutors tell me I'm damaging my lungs however carefully you use a spray booth set-up. It does give such a good smooth finish! Sometimes I use a liquid PVA I bought for book-making, but find it difficult not to end up with buckled paper even when I leave things to dry under a weight.
Now I'm worried about both our lungs, even though I run outside to spray things.