1. Less Bubbles, Mix slow and in one direction. This removes some of the bubbles
2. Bulk, Devcon is nice. Actually I have gone to the two part that comes in the single dispencer, it is more expensive per ounce but easier to use and alway mixes in the right parts
3. Which Type, the longer the drying time the harder and clearer it is. The 1 minute is a bad choice I think because it tends to yellow and doesn't last very long. That is important when you are making stuff like surf candy which lasts for ever. 5 minute is the most popular. I use it the most. 10 would be a better choice then 20 minute. If you are going to use 10 or especially 20min you have to have an electric turner or you will be sitting there for ever.