Driving a Left Hand Drive car in the UK is not as difficult as some people may think. Almost everything is in the same position and it's just like you've been moved over a few feet. The pedals are in the same order, it's not backwards. You shift gears in the same direction, it's not backwards. The biggest thing that messes with people when they first start driving LHD is the indicators and windscreen wiper controls which are on the opposite sides.
15 minutes behind the wheel and you will feel at home with the controls. It will take a day to get accustomed to steering from the right hand side so that your vehicle is positioned properly.
Overtaking is slightly different, as your vision maybe obscured by the vehicle in front of you. You should leave more room between you and the car in front in order to maximise your vision of the road ahead, either that or take a passenger everywhere you go!
If you take frequent trips alone across toll bridges or along the toll roads in the UK, it will be a good idea to invest in a 'Litter Grabber'. I'm not talking a poop scoop for cleaning out the cat, I'm talking about an extended arm for paying toll road fees. Pictured below is an 'Extended Arm' or 'Litter Grabber'.

By gripping a plastic cup in the grabber, you are able to put your change in the cup and tip it into the toll booth's collection bucket. This prevents you having to get out of the car, or lean over and unsafely try and aim your coins, risking one rolling away.
This also works very well at fast food emporiums while using the drive through windows. You can pick up a litter grabber at any Janitorial supplier or hardware mega store for around a tenner or so.
Another important safety factor is self preservation. While at the petrol pump, remember that you have a left hand drive vehicle. Many a time have I got red faced by getting into the passenger side of the car by accident. Besides feeling very stupid, onlookers will not fail to be entertained.
Above all, use your common sense and be extra vigilent on the lookout for pedestrians. Be a little more patient than you normally would be and remember to add a little more space than you usually would.