[navanit]

First, think of what you will do if your client refuses to increase your rate. What is your BATNA? Are you prepared to walk away?

If, after rejection, you plan to continue with the client at the same rate, you will need to make sure the negotiation process does not sour the professional relationship moving forward. This means making sure that you're emotionally prepared to be rejected and also negotiate in a manner that does not come off as aggressive or manipulative.

The best way to ask for it is to highlight the clear benefits you have delivered already and to paint a vision of continued benefits moving forward and then ask for your new hourly rate. Ultimately it's as simple as that.

You will need to overcome objections be referring to the "market rate" and positioning yourself as referring to objective external standards.