As an extension of my goal to amass power, I'd work to attain followers.
1. Unlike most "villains" I wouldn't be an ass to my followers. I will respect them as much as they respect me, not kill them for certain mistakes, and reward them for success.
2. That said, treachery is everywhere. Make sure each and every underling is spied on by other underlings, so they don't turn out to be loyal to the opposition or, worse, another overlord.
3. Help the downtrodden. They make very good recruits - pay for their loved ones' needed operations when so many turn their backs on them, feed the starving, give gifts to the poor, remedy illness and injury... hospitals are as much a weapon as guns!
4. If I find enemies, I will deal with them quickly and without cumbersome, elaborate scheme. Execution will be used unless I can turn them.
5. If possible, harness any supernatural power I may possess. This will come in handy with punishment and reward alike. Mastery of both dark and light also opens up many doorways than just mastery of one.
6. Infiltrate the ranks of -or even create - my opposition, regardless of if I'm in power or seeking it. By creating a false foe, I can keep my followers and the general populace paralysed and supportive.