My method for potty training (I'm a nanny so I've done it many, many times) is:
Wait until they show some signs of readiness (usually between 2 and 2.5)
Do a week or so of build-up chat. Explain that the nappy fairy will come and take the nappies away and they will use the potty and/or toilet. Read lots of books, watch any potty training specific kids shows. Take them to choose some big girl/boy pants.
For yourself, clear the diary so you can stay at home for a few days. Stock up on stickers and sweet for prizes. Get some bed pads or puppy training pads to save the buggy/car seat/sofa. Tell yourself (as well as the child) that the nappies are gone forever, don't give up.
Put the nappies out for the nappy fairy. Wake up to find them all gone and something else left in it's place.
Take the bedtime nappy off and start potty training. Leave bare bummed at home. Expect lots of accidents. Lots of needing to be reminded.
When an accident happens be disappointed with the situation (but not with the child). Get the child involved in any clean up, always make wetting themselves/soiling themselves more effort than going to the potty (for example, in the early days I would let them watch TV while on the potty, but if they have an accident TV goes off while we get changed and clear up). Never be angry or frustrated with them, but it's ok to express disappointment that there is wee on the sofa/floor etc. i.e. it's not ok to soil yourself, but you're not cross because they're still learning.
When they have a success I would be very happy, lots of praise, sweet and a sticker and lots of talk along the lines of 'oh this is great because now we can carry on watching Bluey/painting/playing dolls and we don't need to change your wet clothes'.
I would expect to see some progress within three days and good progress by the end of a week. After two weeks I would expect them to be potty trained (I..e able to tell me they need the loo in good time the majority of the time and to be able to hold it for a few minutes while we find the nearest toilet). Occasional accidents are normal for most children into early primary.
I would introduce pants once they've got a good grip of the potty training, maybe day 4/5/6 depending on how it's going.