Not being unny Emilia but if it is something that you do not do then it is best not to offer, domination is a natural sense of being.  I am a dom and as one it is something comes naturally, you never need ideas or need to steal it from someone else it is just something you pick up, if it is something you want to pursue see if there is a pro domme who would be happy to train you.

You need to be very careful when offering domination.
As Fluffy Bunny said it is a sense of being and often/usually a lifestyle choice.
Some acts of domination can be extremely dangerous if not carried out properly, hygienically and safely.
It is not just a case of "being nasty and mean" as I've seen and heard it referred to before now and which is quite insulting to a dominatrix.
Sorry I don't mean to sound a bit high and mighty over this but it's really important to get it right, cover all safety aspects, and it is having the air of a dominatrix and the whole attitude you portray when dealing with domination. It is about giving them just a look without saying anything, the way you stand and walk, even sit, the way you hold yourself. You should be able to command without raising your voice, just a whisper must have an effect.
There is so much to true domination and being a dominatrix, Fluffy Bunny is so right when she says find a pro Domme to train you.

If a client contacts an escort rather than a dominatrix, he often just wants fetish services rather than true domination. Have some nice pictures taken in thigh boots, and nice black lingerie. Men often want bit of tie and tease, playful spanking, or simply be seduced and told what to do, often pretending he's submitting reluctantly. It's a good idea to devote the first 15 minutes or so to just sitting down with the guy and chatting about it over a glass of wine. You may want to ask him to tell you about his best domination experience, his worst session, or even his favourite wank fantasy. Sometimes talking about it, and being listened to, or recounting horny experiences (real or imagined) is a big part of what they want. I often find over half the session is taken up just by talking, without the client feeling short changed.

You'll find a lot of information on youtube, amazon has lots of literature on femdom, and of course there's stuff all over the net. Best to do a bit of research rather than advertise a service you're not comfortable or confident with. A couple of negative reviews may do your ratings a lot of harm, so I would really recommend you do some reading before you officially offer the service. In the meantime, why not specialise in playful tie and tease? You can experiment with blindfold, nipple stimulation, gentle anal play or prostate massage, face sitting, or tease a guy cowgirl style. It's a lot of fun, it's creative and stimulating, and engages the mind, as well as the body. Don't stress about it - go for it! Once your confidence grows, the sessions will fly by.