There's a lot of useful advice in this thread. I just have to decide which will work for me.
I think I'll try the giving up of porn & wanking for a period (as yet not determined) before a punt. Maybe a week before? I've found that, as I've become older, it is harder to get a deliberate hard-on - I have to force it there with porn rather than just the images created in my mind. When I realised this was happening (it crept up on me), I went to see my GP and he ran a series of tests. Turned out that I have something called 'Glucose Intolerance', which is a mild form of diabetes and can be handled by diet and exercise. GI slows or prevents blood flowing to the extremities - I often have cold feet and/or hands....and guess which other extremity is affected! The GP has prescribed Sildenafil 50mg tablets with the advice to take one an hour before sex. I've adapted this to taking one an hour before a punt and another one 40 minutes before the punt. That seems to ensure I have a hard-on when leaving the shower (assuming I'm suitably turned on by the girl) and also appears to help with maintaining hardness throughout the punt. Also, I extend the foreplay (roleplay or kissing, etc) and this also seems to help. Plus, I avoid condoms - not for penetration, of course. I mostly request OWO and CIM these days.
I wonder how much of this is pyschological? I guess I'll find that out on the day I set off for a podge and discover I've forgotten my tablets. Bm