Practice concentrating and focusing - Formulas, like those in both math's and physics, require extreme concentration and focus. You can build concentration by playing games like chess or sudoku, improving your sleep, meditating, and exercising.
Use mnemonic devices to remember - A mnemonic device is a learning technique that helps your brain retrieve information from your memory.
Practice - This is the most obvious tip but the more times you use the formula you want to remember, the more likely your brain is to retain the information. Solve problems that use the formula.
Understand what each formula means - There is meaning to every formula out there and the sooner you understand what each element means, the easier it will be to remember the formula.
Write the formula multiple times – This goes hand in hand with practicing but even writing the formula repeatedly can help your brain remember it.
Keep yourself healthy – The healthier your body is, the healthier your mind will be. Get an adequate amount of sleep, eat foods that are nutrient-heavy, and spend some time exercising.
Keep the formulas in your line of vision – Write down the formulas and stick them where you will see them every day. Your brain will remember them subconsciously.
Stay away from distractions – When you are studying or practicing math problems, keep all the distractions away. Give complete, undivided attention to the task at hand.
Use flashcards: Write the formula on one side of the flashcard and the explanation or usage on the other side. Test yourself regularly with these flashcards to reinforce your memory.