I use candles, and have placed hypnotic triggers in my subconscious to achieve this, should the candles take too long.
Some use tools, such as a pendulum, which can be simply a necklace and repeat a phrase to induce themselves. Each person has a different method, so my advice is: find a method that is easiest for you after some experimentation! We are usually our own guinea pigs when it comes to developing our own techniques.
Good luck to you, I admire your patience.