Defishing, I see you're in Dover, so am guessing you're either fishing the local ponds or some of the tidal rivers here in MD. (Or perhaps the Nanticoke near Seaford). I've been fly fishing for bass for a long time, and the one thing that got me to catching some decent fish was to change my mind set. This of course will depend on the rod weight you have. I started with a fiberglass 8 wt, which was a better size for bass than the panfish I caught near home.
If you look at the majority of lures intended for bass, they're in the 3" to 5" size range. There are longer, particularly with plastic worms, but most fall into that range. If you're going to use flies, then use something of a size that will interest the bass. My first times fishing for bass was with smaller size flies, because that's what I had been using for panfish, and with success. I also caught some bass, but they were all 12" or less.
No offense to what the others have posted, as smaller flies will work on bass too, but a size 6 Woolly Bugger IMO is a panfish fly. If you have a rod that can cast a 2, 1 or 1/0 size fly, then that's what you should be using. Flies in that 3 to 5" range are what you need to be using.
As near as I can remember, the first larger bass I caught on a big fly was about 2 1/2 lbs. Much larger than the dinks I had caught previously. I was using a yellow & red Seaducer, tied on about a size 1 or 1/0 hook and about 3 to 3 1/2 inches long. That sealed the deal for me, and I've been using big flies for bass ever since. I still use some smaller flies, as there will always be times & places that it's necessary, but most times bigger is better.
However, I also learned very early that stealth & presentation are as or more important than the fly size. Flail & flog the water & you're not likely to catch much, except perhaps with luck a few panfish or dink bass. Larger bass do not get to be larger by being careless. Don't rely on luck. So, work on your casting technique & learn to cast those flies so that you make as little disturbance as possible. Bass are not trout, and don't require delicate presentation, but they can be spooked by careless casting.
Stealth is something I do as much as practical, often even to the point of wearing camo when targeting bass. From a boat or other watercraft it's not as much of an issue, but I've experienced enough situations where I know I alerted the bass to my presence & caught nothing, even though I knew they were there.
If you fish from shore, wear clothing that helps you blend in with the background, and when casting do so with purpose. Make every cast count. Learn to cast accurately so you can place the fly on target the first time. Often, repeated casts to a likely spot is necessary to get a bass to take the fly, but that's mostly because they may be reluctant to move far or are not seeing the fly. So accurate casting is important. Beating the water is not good for productive bass fishing. Repeated, purposeful & accurate casting can be important. There is a difference.
As far as fly patterns for bass, there are many good ones. Use something that imitates prey in the waters you're fishing. That's a good place to start. Bass are not often particular, so colors are not usually important, but you will find there will be certain colors that will work better than others. In the 50 years I've been fishing, I've caught more fish on 3 colors (flies & lures) than anything else. White, Black & Chartreuse. I use other colors too, but these 3 have been the most productive.
I'm quite old school & use Deceivers, Seaducers, Clouser Minnows, Half & Half's, Murdich Minnows, and some rabbit strip flies for much of the bass fishing I do. I also like big poppers & sliders, and Gurglers. I tie many of the flies I use and often they're tied on 1/0 to 3/0 size straight shank worm hooks, even the topwater flies so they're in the 3" to 6" length range.
However, I also use an 8, 9 or 10 wt rod, so if you're outfit is lighter, then you'll need to scale the fly sizes to best fit the rod you use. I've fished for bass quite a bit with a 6 wt too, but the bigger you go with fly sizes, the heavier the rod that's needed for practical & efficient casting.
Check out the various other posts on the subject as argail has suggested. There is a ton of information already posted that should help you gain further knowledge.
I live near Annapolis, but most of the fishing I do is in the tidal rivers on MD's eastern shore. Perhaps we can get together sometime & chase some bass. I have a Gheenoe that is awesome for those shallow rivers & creeks.