If possible, have a mark distinguishing actions as a mod and as a user
I am going to give you two different examples.
One is from moderating a community themed around speaking Russian language properly. It was in a Facebook-esque Russian social net, vk.com. When I spoke as a user, I used my normal profile and posted normal comments. Noone could even know that I am a mod if I didn't say it.
When posting as a mod, I just had to press a button. The post appeared to be posted by the community, not me, and, conversely, noone could even see my name, only other moderators.
The other example is from being an in-game admin in Persistent World, a role-playing modification to a game called "Mount&Blade: Warband". Because of the focus of this mod (role-playing) being very different from the focus of multiplayer of the vanilla game (slashing everyone you see into pieces), most of the new users didn't understand how things go by us, and constant admin supervision was needed to keep peace. The role of the admin was mostly to respond to users' complaints and tell who is right and who is wrong in each situation, applying punishment if needed, and sometimes providing other minor help.
Essentially, my admining time and my playing time were distinct. As a player, I could see that admining is needed (some user asks for admin help) and switch to admin mod, but it was considered not OK (and sometimes even forbidden) to start playing as a normal player if being the last admin on a server. What is more important, if I, as a player, had a dispute with another player that would normally require that a player makes a request to an admin, I was not allowed to make any actions myself, I had, as a normal player, to write a complaint that would be reviewed by other admins. Of course, if I needed to stop a user on a rampage of rules violations, it was another story.
In my admining state I could see admin chat (players' complaints go there, as well as other admins' messages), I had a distinct outfit, I had special admin in-game abilities that were certainly not suited for using as a player.
As a normal player, I was not different from other people in any way. Only my nickname (which is very easy to change in this game) could tell who I am.
In both places it worked perfectly, hence I am definitely suggesting said techniques.