I have been working with resin for almost 6 years and have had my share of successes and failures.  Here's a few of my tips on what it takes to get a good mix to make sure your resin cures properly:

1. Use separate mixing cups with measuring lines (ounces, drams, etc) when measuring the resin and hardener. That way if you overpour one of the components, you won't have to waste any.  Pouring both into the same cup and not being exact means your resin won't harden correctly and you will be left with a gooey mess.  I also watched a video recently where someone poured the resin from their bottle into the bottle cap, then into a single cup.  That's not necessarily the best either.  (Especially when you put the cap back on the wrong bottle and it cures shut.)

2. I like to pour the hardener (from its own cup) into the resin (in its own cup) in a slow stream (like making a cake) while I'm mixing. I think you get a better mix and fewer bubbles that way.

3.  Mix thoroughly for two minutes or so (depending on pot time of the resin you're using).  Don't whip the resin, but keep your stirrer on the bottom of the container.  Go back and forth, around in a circle and a figure eight pattern.  Occasionally scrape your stirrer on the side of the cup to make sure you're getting the hardener thoroughly mixed into the resin.

4. I like to use my resin right away, even if there are bubbles. There is only a limited time you can use the resin before it hardens. I can always go back and get bubbles out.

5. I think there are safer ways of getting bubbles out of resin than using a torch. One of my methods involves using a hot air gun or a hairdryer to blow over the top of the resin to pop bubbles.  Don't do this for too long or you will melt your mold!  You can also blow lightly with your breath through a straw.  The combination of the heat and carbon dioxide will get the bubbles to pop.  This method only works though if the bubbles are on top of the resin.  Draw them up to the surface with a toothpick first.

6.  Use extreme care when pouring the resin directly from the cup onto your project.  It tends to come out in big globs and will overfill quickly.  (at least that's what happens to me)  Pour slowly or use a toothpick or stir stix to drop the resin onto your project.

7.  Dry, dry, dry!  Resin hates moisture, so make sure everything you're working with is very dry.  If you're reusing mixing cups, make sure there is no moisture left in them and make sure your embedments are completely dry (and sealed if necessary).  If you're working with a resin that is moisture sensitive (like polyurethane), you may need to use a dehumidifier in the room you are working the resin (especially if you live in a humid environment like Florida!).

What other tips do you have?