The most important step in this regard is to learn the windsurfing from an experienced person. People often underestimate the importance of learning from a qualified person and start taking classes from anyone they feel comfortable with. Remember that, windsurfing is a very technical game that is played on a variety of levels. In order to master windsurfing skills and jumps, it is highly recommended that you learn the basics from a professional. For this, you can ask your friends or colleagues for recommendations or you can search over the internet. You will find plenty of institutes and person who are willing to teach you windsurfing within your budget.
Go windsurfing on daily basis
Remember that windsurfing requires a lot of practice, thus you should do that after regular intervals. Not to mention, the upside-down jump demands that the surfer should have complete balance over the board, thus you must practice as much as you can.
Learn the trick
The upside jump not only requires balance but a lot of courage. For this, you should be able to face the strong wave of sea coming towards you. Remember that you would have to move towards the wave and reach to the top of it. After you have reached the top, you will be required to put your body weight backwards and spin the board as you want to perform the upside-down jump. Remember that there is only a little time, thus you must be as quick as possible to complete the flip over. For this, you should look for moderate waves and do not go for the heavy ones in the start.
Now, you should not lose hope and keep practicing until you master it. You must look for a clear weather and only then practice the upside-down jump.