Read the handbook
Of course if you bother to read the C337 handbook (quite thin) and understand the fuel system and basic (Continental) fuel injection system then starts and operation are hardly a black art. At the end of the day the machine is still a 'twin' that has some extra systems from a single, and although lacking the classic asymmetric handling issues it still needs to have its 'errant' engine identified (no dead leg help here) and the correct action taken. It was the first twin I flew (a STOL version) and allowed operating into 'strips' a normal twin could not venture. However it still needed to be operated bearing in mind its single engine capability and engine temps always watched. My next twin was the Seneca (from normal airfields) so was less of a jump as the lessons of single engine performance was already implanted, and just the 'asy' bit to learn. Never as much fun as the 337 which could haul a full load out of farmers strips and do a shed load of aerial photography with its high wing. As alluded before really needed a 'stronger ' engine for commercial ops. The French offered their Reims built ones converted as a budget ground attack machine with miniguns and rockets !!!!! Prob OK if the opposition only has swords and spears !!!! , they also offered a marine rescue version that could drop liferafts.