Masking fluid problems please help

Hi every one :) I have a big problem with masking my paper with masking fluid and I need help please! I have just started experimenting with watercolours and inks. I am working on a painting that is basically a colourful subject in the middle of a white 50x70 cm white paper. the subject is quite small and colourful, I need to preserve the paper white and clean all around it. but for some reason every time I manage to get stains on the paper, tiny accidental drops or smudges here and there and I can't figure out a way to remove them, so I have to start all over again, this is my forth attempt and Im getting very frustrated. To remove the stains I have tried every possible suggestion available online but none worked. I have also tried different ways of masking my paper: Masking fluid seems to be the ideal way because the paints can't bleed underneath it, BUT I have a big problem, when I take the masking fluid off it seems to peel a layer off the paper and the masked areas seem to be more matt so iif you tilt the peer in the light , it looks like a stain.not nice. I have tried the windsor colourless fluid on a few different types of quality watercolour papers and boards, they all peel to a degree more or less. Im not sure if Im doing this right but here is how I use the fluid: I apply it with a brush, on bone dry paper, not too thin , not too thick.all around my subject, then I paint the areas that need colour, let it dry completely and the peel off the masking very gently. Also I need to mask all the white areas of the paper to prevent accidental stains (my brush keeps jumping out of my hand and messes up the whole thing!lol) but when I tested this it seemed like getting the masking fluid off such large area was impossible. I would appreciate it if you could suggest the best way of masking large areas please. maybe Im using the wrong material? Thank you so much x