I have a graphic memory of the white board in elementary school. The teacher always have left and right written in the corners. If I can't figure my left and right I just close my eyes and see the white board. I haven't tried this mayself but maybe put a little toy car on your desk and remeber the driver sits on left side of the car. Perhaps even write left and right on the hood and/or bumper. Just make sure the car is facing the correct way.

I think about holding a pen/ pencil or writing my name in the air. I know i am right handed so the hand that wants to pick up the pen must be my right.

If you wear a ring on one hand, or a special ring on one hand (I wear a wedding ring on my left hand), you can use your thumb to feel for it and that will tell you. It works great for me.

Hold out you hands palm down with thumbs extended. The hand with the big L made with your thumb is left.

Or is this the hand trick you say doesn't work for you?

Are you right handed? If so repeat to yourself I write with my right. Sounds better out loud.

Perhaps you might find it useful to consider that you read from left to right. Left first, L is before R in the alphabet.

I have always used the hand writing trick. My son has this also, he doesn't have the right left problem. Strange.

i just think what hand does things best