Once the Mechanic finishes retreating or rebuilding, clear the area of Agents, and speed up his construction process.
In case an allied Mechanic has his sentry gun destroyed, place a mini-sentry on the exact same spot and fire away, buying him time to move his equipment to a different spot, or to rebuild his weapon.
A wrangled mini-sentry has the fire rate of a level 2 and 3 sentry.
The least practical spots for a stock sentry work wonders with a mini-sentry, due to the building's disposability.
Always deploy the weapon pointing behind you, to easily cover a flank when making a push.
behind a bush, will make it even more difficult for an opponent to pin down.
Hiding the weapon to only have the barrel stick out, i.e.
Mini-sentry guns shine in their ability to counter overextending mobility classes.