First and foremost, be clear about your absolute minimum.
Research the pay scale of the company and industry average pay.
Never mention any pay expectations on application forms or cover letters.
If your job is in high demand, refer to it.
It is also fine to say that you have other interviews, but don't act too self-assured.
Don't be the one to bring up a salary figure.
If it's unavoidable, mention your pay range, but say that this is up to negotiation.
Talk about your previous achievements in higher productivity,...
...cost savings and your general benefit to the last company.
This can improve the salary offer.
Once a salary figure is on the table, indicate that you are considering it, but keep quiet.
The figure could go up in that short time span.
Though money is important, think about the whole package.
Ask about the frequency of pay increases, perks and additional bonuses.
In any case, be well prepared and apply a little psychology...
...and your negotiation skills to get the best offer.