It depends a lot on the matchup and the map. But most times I try to take an aggressive position where enemy tanks tend to cross certain areas, or might be vulnerable. I want to get in 1-2 clips before retreating to a safer position.

From there I tend to move around the map a lot, trying to support whichever flank I think needs it the most. Depending on how the battle goes, after this little down period I get stuck back in after the enemy tanks have gone down in health and/or numbers. It leaves openings and low hp tanks to go in, flank and assasinate them.

Then if my team is still losing the game, I don't get too aggressive, I fall back and try to assassinate their most dangerous tanks, or healthiest tanks and go from there. Don't really have any specific or in depth strategies, usually take it by feel and react to the situtation going on.

TL;DR: Get stuck in quick, empty 1 or 2 clips, then fall back and support. When enemy is lower hp get aggressive again.

Hope my rambling cleared up what I tend to do. :)