Some tools I use :
Mr Surfacer 500 :
I use it a lot everywhere, not diluted in small seams, or diluted with Mr Color Leveling Thinner for small scratches or hard to reach area.
When dry, small grit sandpaper or Q Tip diluted in Mr Color Leveling Thinner to remove excess.
Mr Diluted Putty :
New product I use, I find it a little soft when dry, but it’s extremely easy to remove or sand it and very liquid so easy to applicate and use capillarity to access hard to reach holes.
Tamiya White Putty :
The classic, not very used as it tend to goes out of the tube very quickly and I loose a lot of it every-time I open it.