Clear water

For these conditions, you want to use flies that are very realistic with mild colours because the fish can see every detail much better than any other time. Examples: Dave's Crayfish (brown), Hellgrammite, Muddler Minnow, mice, deer hair frogs and other bass bugs which are dull in colour and have a lot of detail.

Stained/muddy water

In this type of water, the main idea is to get the fish's attention. To do this use bright flies. Bass usually hang out in shallower water in these conditions. Examples: Sneaky Pete, brightly coloured bass bugs, Whistler, and Lefty's Deceiver (smaller version).

Overcast/windy

Bass will become more active under these conditions. Their strike zone will enlarge so cover lots of water. You can do that by using the fan cast (click for demonstration). Bass bugs and other large, light flies become hard to cast in windy conditions so flies like the Clouser Minnow, Dave's Crayfish or the Muddler Minnow will cast with more ease. If it is just overcast, bass bugs are a good bet. Flies like Whitlock's Hare Water Pup, diving bugs, Barr's Bouface, slightly weighted Wooly Bugger, frogs, and other hair hare worm, bass bug, and minnow imitation flies are good choices for these conditions. Colours depend on water clarity.

Bright/sill

The bass' strike zone will shrink making catching more difficult but is still very possible. You can choose to either fish deep, or to fish the shallower, sun-blocking cover such as weeds and logs. Weighted flies such as Dave's Crayfish, Wooly Buggers, Hare's Ear Nymphs, Hellgrammites, and Muddler Minnows are all good flies for getting deep. Flies such as the Marabou Leech, slightly weighted Wooly Buggers, and various minnow patters work well for fishing shallow water structure.

Morning

Fish structure like crazy. Bass will be feeding quite heavily around structure where food is available.

Noon

Fish cover and deeper areas. Fish all structures thoroughly. The bass' strike zone's will be pretty small so you should every structure or hole very thoroughly. Dark blends of yellow, red, and green are good all-purpose colours during the day.

Evening

Quite like morning in that bass are feeding heavily. Bass' strike zones are now quite large. Cover lots of water and use quick retrieves. You may want to go topwater with frogs, poppers, bass bugs, diving bugs, or any other topwater flies.

Night

Any noisy topwater baits. Black is a good colour because it shows the silhouette of the fly to the fish.