Have an answer to every objection. First figure out all the ways you would object and make sure you have an answer, then note down any objections you don't have an answer to during your process and make sure you have a good answer next time.

And if you're selling a product, make sure you know your competitors well because a lot of objections will be in the form of "but competitor X does this, how do you solve that problem?" and "what do you do that X doesn't do?". So you better know X really well because the person you're talking to already does and will know if you're making stuff up.