I definitely think it's easier to jump right in. It can be messy/frustrating but it happens faster that way.
Each of my boys potty trained totally differently. B used to sit on the little potty and watch a show until, literally, pee just came out. We'd make a big deal but he never really told me when he had to go. One day I decided to put him in underwear. It was summer, so we went out back (cleaner that way!) and he peed through like 5 pairs of underpants in 2 days. Then Monday came and it was like magic. If he's had 3 accidents ever since then, that'd be exaggerating. The poop part and the night part took a little longer, but I cared less about that!
Little Guy had no interest in sitting on any potty- big or regular. I tried the underwear thing again about a month after he turned 2 and he did really well. Couple accidents the first couple days, but then he'd tell me when he had to go and we'd run over. He had to stand at the regular toilet like the big boys- he refused to sit. That made the poop part quite difficult at first but now he's got it all down pat. He was in diapers for nap/night, but we got out of that quickly.
I am a fan of pull-ups, if you're going out or long car ride. I treated them like underwear for my boys and told them to keep them dry. While you're home, I'd try underwear or even naked for 20 or 30 min a day if you have that time to really pay attention. It's like they know there's nothing there to catch it and they become more aware! All kids are different, but I think that consistency is what makes it work- and of course the bribery of stickers/candy/special character underpants/whatever!
You have to be daring. If you put them in diapers just to be safe, they're probably going to keep using them.