Jetlag is unavoidable when you're making a long distance flight across time zones. But the effect of jetlag can be minimized. Here are a few tips.
First, travel well rested. Of course it's impossible to be fully packed too far in advance because some of the things you pack are items you use on a daily basis. But if you can, pack most things in advance so that you aren't frantic when you leave the house.
Then, if you have a late night flight resist the temptation to eat the 10pm meal they will serve you on the plane. If you've already had dinner, a 4th meal is only going to add extra unwanted calories. Instead get as comfortable as you can and try to sleep.
Even if you can't get a deep sleep (I can't) resting with your eyes closed is better then watching movies.
When you arrive, leave your luggage at the hotel (likely your room won't be ready) and go for a nice walk. Try to get your bearings. Finally, drink a lot of water to help you rehydrate after your long flight.
If you have to have a nap, limit it to one hour in the afternoon. Then try to stay up to the time you usually go to bed at home. Your goal is to adjust to the local time zone as quickly as possible so that you can enjoy your trip.