Just make sure your reseve actually works. One time, after having the tank replaced, the mechanic screwed up on the interior tank feeds to the petcock.
There is one longer feed tube that, when the fuel reaches a certatin level, will no longer convey fuel to the petcock when it is set on main. Switching to reseve allows fuel to flow to the petcock from a lower level in the tank. When the mechanic reinstalled the petcock into the new tank, the regular feed tube got dislodged. This resulted in the petcock taking in fuel from the bottom of the tank when on the main setting. When the engine ran out of gas, there was no fuel left in the tank, and switching to reserve did nothing because the tank had already been drained from its lowest point. Be careful about relying on reserve.
However, if your tank is one where the tank actually goes lower than the frame tube on both sides (some tanks do not - my original tank did but my replacement tank does not), you should be able to slosh some fuel from the right side to the left side where the petcock is located and get a few more miles after you think the tank is dry.
Also, on the topic of annoying failures to start, I have a habit of setting my helmet on the tank in such a manner that it leans against the right handset. At times, the helmet flips the kill switch. When I come back to the bike, I wonder why it won't start. I have since learned to always check the kill switch first when there is silence when I press the starter button.
It is quirks like these that make the R65 so endearing.
k_enn