Men are visual creatures, so you might ask him if he likes porn.

Others are sensory and depending on their comfort level may enjoy being blindfolded and teased.  

Ask him if he has any "forbidden fantasies" (but make sure he respects your boundaries).

sometimes helps. too...he my like suggestive or "dirty" talk.  Also a provider's auditory responses can help.

They work wonders, but have to be sized properly. The medical grade silicone are best, but look a little dorky, but once you get the idea, shop around for more stylish models.  Experimentation with different ones is a fun activity.  

http://www.adameve.com/adult-sex-toys/penis-rings/sp-titan-men-tools-penis-ring-14589.aspx

Sometimes it doesn't have to get hard to get off. wooohooo.

But if it is a matter of technique to get there all the above tips are great.

Prostate massage?

If the guy (and you!) are OK with it, a nice gentle probing of the prostate together with a HJ and/or a BBBJ will do wonders. In addition to increasing the strength of the erection, it can really intensify the guy's orgasm when it happens. In case you wonder, I do speak from experience. Ciao!

has led me to forgo sexual intercourse and focus instead on massages, sometimes with prostate stimulation (which really does enhance the happy ending!) or simply have a bbj.  I do use viagra, but while it helps to get erect, not always able to sustain it nor get a complete hard-on.  But I can still reach orgasm and with the prostate stimulation, really explode!

It is the connection that is what we all seek...once that is there, sky's the limit of where you can creatively roam.  Some men don't let themselves even focus on cumming or not- if it happens of course that is great, but the fun and games and time together make it worth it for many men.    

I have grown to understand that the openness we share as providers to just trying things, having an open and playful spirit is really the key.  Remember the brain is the most sensual organ in the human body.

re-assure him that there will always be another time in the future.

Cuddle, caress, and talk, which is always very much enjoyable.

Then, perhaps while that is going on, you might try starting something different, unusual, or totally surprising or un-expected.    It could begin as something seemingly very small or perceived as insignificant.  That can often roll on and grow like a snowball.

If it still doesn't happen, your pleasantness and understanding will always make it worth my time.

with some prostate play...he'll thank you later

http://www.pornhub.com/view_video.php?viewkey=885296534