When making bubble, I'm usually going for yield over quality, as its' usually after outdoor season and I have an *ahem* bit of trim to run...
That being said...some very good points in last post...
I completely agree with #2. ALWAYS STIR BY HAND. I don't care if you're using 1 gallon or 20 gallon bags. With 20 gallon use an oar.
99.999999% of the time hand-stirred will be of higher quality than blended. Also blenders can damage your bags.
I also agree with #3, but I go one further. I like some chunks, but a lot of crushed ice. Snow is even better. The best quality bubble I ever made was 100% snow used, added frequently. I like my water to get almost slushy-like, maximing the amount of surface area for trichs to come into contact with, thereby more easy to break off.
Excellent point about the size of gland heads with indica vs. sativa. I find most often (when running for personal stash) that the 73 bag often contains the magic with indicas, the 45 bag for sativas.
I also like to do the work (stirring) in one bucket, and the pour-through process in multiple other buckets. Speeds things up IMO. I also freeze my trim beforehand, don't remember if that had been mentioned or not. And I prefer using fresh trim.