Relax, close your eyes and visualize a candle. Make it any size and shape you want it. put it in any holder you wish, but remember to make it solid. It should be as 'real' as possible. Next light it however you want, with a match a ball of flame, whatever. Now concentrate on it and hold it there, real and lit, just like a real candle for awhile. Try not to let it waver (other than the flame flickering). This is to build up you visualization stamina.
Next, change the size of the flame, make it bigger or smaller, see the colors in the flame as it gets smaller. Send a breeze across it. Watch the flame dance. Is there wax trickling down the side yet? Change the color of the flame. Heck, go on and change the color of the candle itself. Change its size and even the holder. Remember to keep it 'real.' This helps teach versatility.
Now, can you smell the candle smoke? Is it a scented candle? If so what scent? Really smell it. Now whether it was scented or not, change the smell of it. Do that a couple of times, each time really smelling the scent of the wick burning and the scented (or unscented) wax. Now mentally run your fingers around the candle holder. Don't lose the scent or the 'reality' of the candle. How does it feel, rough, smooth, cold, warm? Now feel the candle itself, cool and smooth under your fingers. Pass your hand near the flame. Feel the warmth of it. Keep doing this, using as many senses as possible at the same time to explore the candle. Try not to let the scent or the visual drop at any point in time while you are feeling it. This helps you learn to incorporate your senses together in a visualization.
This is a lot like exercise number two. You need to relax then visualize a piece of fruit or vegetable or some other piece of food as close to the natural state as possible. Imagine it as a real solid piece of whatever you'd like (I'll use a strawberry). Really look at it in your mind just like you really looked at the colors in exercise one. Touch it, feel the texture of the skin, the tiny seeds on the outside and the almost fuzzy crown of leaves at the top. Smell it, the ripe fresh picked scent of sun warmed strawberry. Now bite into it. Feel the juice hit your tongue, hear the sound as you bite it. Taste the sweetness of it. Really experience it in as many ways as possible. Smell it as you taste it, feel it in your mouth.