I am my ideal landlord
. I let out several properties: I don't use an agent, and never have done: I find the tenants, do the referencing, contracts etc myself.
I wouldn't bother with Prosecco. The thing that makes my tenants most happy is the fact that I deal with problems immediately, regardless of when they arise (so they know they can text me at 10 PM on a Sunday if the water has gone off, and I will do something about it). It's sometimes a pain when they tell you that the kettle needs de-scaling, but I will always call in the following day to do little jobs like that. In terms of bigger jobs, it's an idea to get all your services, boiler and white goods insured (British Gas and Dyno both do decent policies, and will send someone immediately if there's a real problem).
Never visit without warning them first (supposed to be 24 hours in advance). And if you do have reason to visit, remember that their housekeeping might not be up to your standards, but that's fine so long as they leave the house as they found it when they move out.
It is, of course, easy for me to do all this because I live close by. I did once have a long-distance let, and it was much more difficult. In fact, I sold it due to the problems of trying to keep on top of it from a distance.
I don't think you necessarily need an agent, though if you don't use an agent, you will need someone 'on the ground', who can sort out day-to-day problems that might arise. You would probably have to pay them a retainer (I do this for a couple of other people), but it may well be lower than an agent's fee.