If you can't persuade people to be reasonable, be bolshy. This is how you do it, it worked for me, twice, in two different homes. The first time my neighbour took no notice and I was eventually paid over £1,200 in parking charges and legal fees; the second time the threat was enough to stop the trespass.
Put up a sign that say Private property. No parking. Trespassers charged £xxx per trespass.
Photograph each CF parking in your space each time, recording the date and time, for billing purposes. For each vehicle send a form V888 to the DVLA (fee £2.50) to find out who the registered keeper of the vehicle is. You have to send a copy of the photo of the vehicle parked on your property with the form.
After a given period of parking, say four weeks, send CF a bill for your parking charges, telling him/her that if the bill isn't paid after two weeks, you'll sue the bastard, and mean it. If it's not specifically mentioned in your rental agreement, search your Council's website for parking charges and penalties. If they list a figure for a penalty for parking in a space where a resident pays for a parking space, that's the amount of your charge per trespass. Where I live that amount is £50.
Once you have judgment against the CF this will automatically go onto his/her credit record, you don't have to do anything for that. It stays there for (I think) seven years after the debt has been paid. If the CF is a property owner you have a further advantage because you can guarantee to get your money eventually, via an equitable charge on their property. The money owed to you will become payable the next time the property owner tries to remortgage, or sell, the property and their solicitor will pay it automatically, she has no choice in that. Until then it carries simple interest at 8% per day, charged annually.
When referring to your parking charge in any sign, bill or correspondence, make sure you call it that, it's unlawful for a private person to call the charge a 'penalty' or 'fine' as that implies you have a statutory authority which you don't; you're simply sending a bill for the receipt of a benefit to which the CF is not entitled.
Yes, this is tedious and costs a few pounds; whether it's worth it or not only you can decide, and why. I'm retired, have time to myself, and am thoroughly sick of the contemptible way we elderly, and disabled, and ordinary working class people tax payers or not, have been treated by this Tory government and the way that attitude has filtered out into the general population.
I'm a disabled retired single lady who can't drive any more, and was seen as vulnerable by two very similar specimens of men who decided they could bully and control me. I showed them they couldn't. The first man's battered wife was encouraged by my standing up to him, to leave him and divorce the bastard. I didn't find that out until several years later. The second bastard is my current next door neighbour whose own parking space adjoins mine behind my garden fence. He actually had the nerve to say to me If you wanted me to stop coming onto your property you should have come to me and asked me to stop. I disagreed. My threat to put his photograph on my blog with the background, and award him the Bastard of the Month title might have had an effect, too. He knows now not to mess with FeistyOldBat. It's quite satisfying. 
Otherwise my neighbours are lovely, friendly and helpful without being pushy, and I try to be the same.