Talk to yourselves aloud or in writing...

This may be out of left field, but I recommend talking to yourself as yourself, rather than as you'd talk to someone else. In other words, cut out any inadvertent signaling in your voice (spoken or imagined). For some this may seem alien or impossible, for others it may be perfectly normal. Still others probably think they do talk to themselves as themselves, but don't.

The reason is just the obvious one that interactions with other people are rarely if ever conducted on a purely rational wavelength, and there's no reason to inadvertently carry those extra distractions over into your own self-talk and contemplation. Maybe no one does this - friendly warning just in case.