Trial and error is what it took, just like anything else. We started with 2 different kinds of epoxy one thin and the other thicker. The thinner epoxy resin seemed to have a clearer finish than the thicker one. However the thinner epoxy was harder to work with. The thicker one was easier to handle and  to work with. The thinner epoxy was almost like water. It would take more of the thinner resin to complete a plaque than it would the thick resin.

Over all we felt that the thick epoxy is easier to finish a plaque with.
As far as the bubbles goes they are very easy to get rid of. You can blow lightly
over it or you can use a straw to blow lightly and the bubbles just pop away.

If you use a straw don't blow to close to the resin or it will create craters in
the epoxy. Hold the straw about 4-6 inches away and blow lightly until all
bubbles pop away. Some bubbles you will not see, so once the epoxy stops
popping the bubbles are all gone.

Using the thicker epoxy and getting rid of the bubbles is the easy part. Now comes the difficult part what happens after you pour.

The way the epoxy resin dries is out of your control. You can have a controlled
environment with ventilation and being dust free but how it dries is just
something you can't control. That is why sometimes you have to do 2 or 3 pours.
We can still sometimes get away with 1 pour, but we have no choice but to do
2 or 3 pours sometimes. We have a high qaulity product which is why we pour it
until it looks like glass.