My dd is rising 3, and completely refuses to use the potty. At all. My attitude so far has been to shrug it off and leave it another couple of months before trying again. She is generally an easy toddler, not given to tantrums etc, but I suspect she has picked this as her Independence Issue, and my response has been to refuse to join her on the field of battle.
But she is due to start pre-school in six weeks, and they insist on them being potty-trained. So there is a time issue. Also, dd seems to be taking against nappies as well, and enjoys taking them off and peeing all over the floor (thank god we have hard flooring).
I've tried sticker charting, reading favourite books on the potty, taking her out to buy big girl pants, using the toilet instead... Now running out of ideas, and feeling increasing pressure.
Dd was refusing quite vehemently for a while. We eventually offered a small chocolate treat after every use (I'd previously sworn that I would never use this sort of bribery). It worked brilliantly and she forgot about the chocolates within a few days. It's not ideal but it was very efficient.
My other epic battle with her was over tooth-brushing, which we seem to have finally cracked through shameless offers of (small) presents every time she lets me brush. Now it's getting established, I've scaled down to a sticker chart (with weekly small present) and hope to phase it out completely soon.
Maybe a similar approach with the potty would work.
And if it doesn't, I could always eat the choc to cheer myself up.