What are the various guaranteed ways to go to heaven ? I think one of them is Kshatriya dying on battle field always go to heaven.
What are the other ways ?
There are many many ways but one interesting way is there for the criminals too. If criminals get duly punished by the king (law or Government in today's circumstances) then they also go to heaven just like virtuous persons.
Manu Smriti 8.318. But men who have committed crimes and have been punished by the king, go to heaven, being pure like those who performed meritorious deeds.