[Mark7]

Single most important tip... TRY to keep ethanol gas out of the tank. Some areas of the country that is not possible.

Also important (as Jay said) turn off the fuel supply and let the engine quit (using all gas in the carburetor) if is is going to sit for even a couple of days.

If you plan on storing it for any length of time, get the gas out of the tank unless it is non oxygenated (no ethanol) gas. That stuff goes bad sooner than you think.

Thankfully in ND I can still buy 100% gas, even 87 octane which is better for small engines but it is about 30 cents a gallon more that the ethanol blend gas. Money well spent when its going in any small engine I own.