I use various modules described as "MT3608" boost converter to step up the voltage from a 2S lipo pack to >12V. These can be found on the usual outlets for a very low price. MT3608 is the control chip for the boost converter, the actual circuit has a few passives and a (very important) diode too.
These are ok for >1 amp or so for a short period, it seems (at least, when boosting from ~7v to ~14v) (they are rated at 2A under some conditions)
But they're mass produced and probably not well tested, they likely don't have good control over their BOM substitution etc, so I wouldn't be surprised if one batch work fine, and the next lot catch fire as soon as they're turned on.
You could also roll your own board using the MT3608 chip and your own sourced diodes / caps / inductor which I assume would be more reliable (I haven't done this myself though).
If you roll your own circuit to boost it, then you can connect the enable pin to an output on the microcontroller so you only boost the voltage when you want to run the motor, I suppose that will increase efficiency. I haven't measured the quiescent current of these modules.