The older I get, the easier it is to admit that I am a trout guy. I would guess that I have a total of 10-12 days of serious bass experience with a fly rod. This does not count strippers. I think I always caught something but, it was always a hoot! Learning to cast those bigger flies and poppers was the hard part for me but it didn't take too much time...just practice before the trips. Whenever I would get time to fish, my simple mind would most often whisper "trout rising" and the bass would have to wait for another day. 

Fly fishing for bass, either largemouth or smallmouth is a whole different deal than fishing for trout. First, and most importantly, bass are way more aggressive than are trout. Second, locating bass is usually way less complicated than finding trout...unless of course the trout are rising. The key to finding bass is structure. Bass are primarily ambush predators and, as such, almost always look for cover from which they can attack unwary prey. Weeds, rocks, sunken logs are all examples of where you will likely find bass. Third, if you bring your trout fly box(es) on a bass trip, there is a very good chance that everything you have is too small. Bass flies are large...very large when compared to trout flies. Bass tend to prefer big food over small food. Therefore, your gear needs to be bigger and heavier so you can adequately cast these big flies that typically have more weight and, being larger, have way more wind resistance. Finally, compared to trout, bass are everywhere...they are a "warm" water fish so do not require the cold flowing water that is typical for trout. The articles below will help you understand the important differences between fly fishing for trout and chasing bass.

As I have said, I am a trout guy and do not have the personal experience to really write about it. In the process of putting this article together, I reviewed several dozen articles/videos  following were chosen as they most closely relate to my limited experiences with bass.

3 Reasons You're Not Catching Bass - by Dave Parsons and Flymen Fishing Co. This article talks about the primary differences between fly fishing for bass and fishing for trout from a trout perspective.

The Inside Secrets of Fly Fishing For Bass - by Bass Angler Magazine. This article is also helpful in helping the trout fisher understand they key differences between fly fishing for trout and fly fishing for bass.

Bass on a Fly - Orvis Guide to Fly Fishing - by The New Fly Fisher.

Largemouth bass on the fly: Tips from the pros - by Mike Hodge and Hatch Magazine.  

Fly Fishing Smallmouth and Largemouth - This is a really good article for beginners. It covers all of the key issues and, as is typical, Orvis has done an excellent job of presenting the information.