What would be the best way for me to ask for a salary increase?

I am near my 12 month period and plan to ask it a little after the 1 year mark, hoping they may squeeze a little dough through. I have never asked for a salary increase before so I am very nervous. This will have to be through email as there is no manager who has their own office so I'll be asking in public. I have learnt alot since i first joined and a few colleagues have also provided me with compliments in my work during this time. In my first 2 weeks there had been a few complaints about me but I am good now (even management has given me a few compliments during this time). I work as a first line IT Engineer at 23k but am hoping for 28K as see myself more as a senior. I do get my work done and even spend time after hours to finish off anything if necessary, I now go on occasional on-site visits to clients sites as well as sometimes assisting in training new users and assisting colleagues in their project work when necessary. I am thinking to let them make the first offer before giving them my figure, if it is less then or equal to my figure,I will ask for a pump, however if it is at my figure then I'll ask for a 1/2k increase - Is this a alright tactic?