Decontamination is often overlooked by the average person. Those that are familiar with detailing clay probably spend an hour claying their car when necessary. There are newer clay alternative products on the market that make this task much faster and easier.

Consider a clay towel (speedy prep towel) or a pad for a DA polisher. There are also blocks that can be purchased. These products last for 5-25 cars and if dropped, can be washed off and reused. They can also reduce your claying time to 15 minutes. The disadvantage to these products is that they are much more aggresive and if used incorrectly, will result in marring the paint. It's important to recognize this situation and make adjustments as necessary.

Place a sandwich bag over your hand and run your fingertips over the paint to feel for contamination and determine if claying is necessary.
After a wash, don't dry your car if you plan to clay, this is a wasted step. Just over concentrate your clay lubricant a little to compensate for the extra water on the panel.
Only use a small portion of your clay at a time. 50-80 grams is plenty. A 200 gram bar should yield at least 2-3 portions of clay.
If you drop your clay, throw it out. Debris in the clay can scratch your paint.
Use relatively slow motions and light pressure. Moving very fast and using a lot of force is going to change the effort from gently shearing to aggressively grinding.
Check the clay bar often and reshape as necessary. Depending on the condition of the vehicle, that may be once every panel or once every square foot.
Use plenty of clay lubricant as this reduces the risk of marring.
Use a dedicated clay lubricant. These are designed to remain slippery even as they start to dry. Soaps have a very sharp cut-off from being slippery to sticky as they dry.
Work relatively small areas and dry them immediately to ensure suspended contaminants don't have the opportunity to resettle on the paint.