Hi Bud !!!
Yeah I usually ride to the other states. Formalities, well you need to get a NOC from the state where you bike's registered. That costs you around 200bux(broker charges xtra).Once you reach to the new state you submit the NOC there and get a new number(incase you are staying long term) & pay the road tax there. Usually its to the north of 4.5k for 150cc+ bikes(1-3 years old). Once thats done you need to submit the receipt at the first state RTO to get refund of the tax that you paid there while registering the bike.
In short, too many hassles!!!
What I would suggest is...Carry a NOC with you and dont bother abot taxes incase its a short term transfer(but keep checking for cops at signals

). If more than a year pay the taxes and get the bike registered there and ride in a relaxed way
Cheers
Soumen...