One of the things that I purchased my airbrush for a long time ago was to do some stencil work. With my titan already base coated, I found the perfect excuse to try some stencilling out.
Here, I'm using some of Anarchy's stencils -- in this case a hex grid. The first image shows me lining up the stencil over the upper carapace of my Warhound titan. I then attach in in place with a combination of masking tape (the sort that doesn't rip paint off!) and blu tac (again - applied lightly to not rip the under coat or base layer off).
The colour I'm using here for the stencil work is a creamy off-white colour. I chose this to be a nice complement to the green base layer that I've already airbrushed in to place on the titan.
The results are very nice. I did go a little bit wrong as I sprayed around the curve of the carapace though - some of the paint leaked at an angle. I should have been more aware of this -- the tip here is to always be at 90 degrees to the surface that you are stencilling. Or at least be at a consistent angle. Still, a little bit of detailed paint with a triple zero sized brush tidied it up to an acceptable level. I'm sure once I've applied a little bit of weathering it will hardly be noticeable at all.
And I capped it off by stencilling half of the head / pilot unit as well. The idea here is that the iconography will occupy one half of the upper carapace and the stencil work the other half. That way, it'll look very identifiable on the battlefield and give it a little bit of a "pop" to stand out against other titans (if needed!).
Later work will include going around the "edges" of the bodywork and selecting a different colour for this (I'm thinking gold or brass to complement the green).