I grease the bar at the end of the day. I'm mostly concerned with moisture causing rust as it is usually very damp around here during "cutting" season. Can't say whether it is necessary or if it even does any good but it only takes a second and I already have the fancy dancy grease gun.
90% of my cutting is milling in hardwood. I keep most of my saw oilers on max and use Aux oilers on the nose of all my bars - even the 20". The aux oiler floods the chain at the nose with oil so the nose bearings get way more lube than a conventional saw would ever receive.
Each time I sharpen the chain, mostly at night in the shop after a day`s cutting. If a chain gets dulled in the woods then I just switch it out for another saw with full tanks and sharp chain.
Pioneerguy600