Hello. Firstly, it's great that you're open to the idea of doing BDSM with your gf, despite it being new to you. Then again, I just realized that you didn't state anything about that, so if I may ask... how long have you guys been trying it out?

Anyway. There's a strange paradox about domming that has some parallels with sleeping: the best way to succeed is to stop trying and just let go. That doesn't mean that you don't put any effort into it; it means that you should stop worrying about whether or not you are pleasing your gf, or whether or not your manner is domly enough. Instead, I suggest you just relax and try to enjoy yourself, enjoy the feeling of control and power and immerse yourself in it. See, if your gf is anything like me and several other subbie girls I know, she will not be happy as long as you just try to fulfil her wishes, rather than doing it because you want to and enjoy it. When you are in role, don't think about pleasing her, rather think about pleasing yourself.

And confidence. Can't stress the importance of that too much. And the best thing is, it's something that most people can learn through practice and experience. Kinda like winging a not-very-well-rehearsed performance, ya know? As long as you believe you're doing great and enjoying yourself at the same time, there's absolutely no reason why you should not do great. There's nothing that kills the scene more than 'Dear, am I doing this right?" midway.

As for ideas for play, there are lots of resources for that -- in fact, you could probably start with the stories right on this site. Granted, many of them are meant to be fiction and nothing more, but some really contain some great ideas that can be applied. The resource sites that are listed above are great too, but a word of caution here: take every piece of advice (which includes this one ) with a pinch of salt. Don't try to conform to the mold of the ideal dom or the ideal bedroom scene which works for others, but very well may not work for you and your gf.

Indeed there should never need to be any reasons for a good spanking. But if you want it to seem like 'punishment', well, any small silly thing would do, actually. 'Is that no panties I see beneath that skirt? Bad girl!' etc. She may want to give you hints whenever she feels like playing, too, anything suggestive or endearingly bratty would be wonderful excuses for play.

Wishing you all the best.