To make a cloud you need three key ingredients.
A drop in air pressure
Fill a clear two litre bottle 1/3 full with warm water. Let it sit for a few minutes so that the air in the bottle can become very humid. This will supply your water vapor.
Next drop a lit match into the top of the bottle and quickly put the lid back on capturing as much of the smoke in the bottle as possible. This will supple your dust partials.
Now you need a drop in air pressure to create this squeeze the bottle. You will notice as you do that the smoke seems to clear up allowing you to see clearly through the bottle. Now to reduce that pressure simply let go.
When you let go the pressure you put on the bottle decreases allowing the air in the bottle to cool slightly. This cooling will cause it to no longer be able to hold as much water vapor the water will condense in small droplets on the dust particals creating a fog, or cloud in the bottle.
Tada! A cloud in the bottle and as long as the water stays warm you can squeeze and let go over and over again clearing and creating your cloud.