In my case, these things were helpful:
-having sex more often (desired frequency) and on a regular basis
-using more non-coital activities, e.g. oral sex, handjobs etc (with or without orgasm)
-using condoms helped a little bit, too
put more time on foreplay so that you will enjoy your intercourse a lot longer.
not sure what you mean but we have used 'maintain' to desensitize the penis so he doesn't ejeculate to soon. it is available in Walmart.