Norman Digger writes

I'll have to give the application of glyphosate a go too. I do use the
stuff, mainly for the drive with a big sprayer. I wonder if it can be
applied to individual weeds such as dandelions with a small artists paint
brush without getting any on surrounding plants?

Yes

But make sure you don't use the same paintbrush for, eg, pollinating
plants, or applying dabs of meths to see off sap sucking insects.
--
Kay