Helping you with phimosis, frenulum breve, tight foreskin, and other male health issues.
Pull back your foreskin whenever you pee. The bathroom is a good opportunity to stretch slightly and also to get used to the sensation of exposing your glans to air. If you are not yet used to peeing with your foreskin pulled as far back as it can go, then you may want to do this sitting down at a toilet rather than standing at a urinal.
Pull back your foreskin when you shower. The shower is another good opportunity to get used to exposing your glans. Since warm water is more stimulating than air, it desensitizes your glans more quickly.
Also, while in the shower, you want to pull back your foreskin to clean things out. Do not use bar soap directly on your exposed glans since it will dry it out. Instead, retract your foreskin and let the water run over it. If you use a body wash, then you can also let the soap run down your body and drip off of your exposed glans.
Adopt masturbation techniques that involve gliding the foreskin back and forth over your glans. The closer masturbation mimics sex, then the more you will be ready for the sensation, especially if you have never had sex before.
I recommend buying a male sex toy made to simulate a vagina or any other similar toy with an elongated canal. Popular examples include the Fleshlight and the Tenga Flip Hole.