Re: Calling missed shots
I shoot almost exclusively by myself so this is something I have a level of experience with. My target is a steel IPSC - so at a distance, it becomes pretty small.
A) Some backgrounds are better than others - dry conditions are definitely better than wet, upslopes better than flat, soft better than rocky, bare ground is better than brushy.
B) Fundamentals, fundamentals, fundamentals - you have to learn to drive the rifle correctly such that you are able to observe the 'moment' of impact. Now if your POI is wet or brushy - you may not see the actual impact, but you visually need to be there in order to have the opportunity to witness the impact.
C) Power down - if you have a high mag optic - power down to allow for a wider field of view.
D) Play the odds - depending on one's ability to call wind, mikes are typically high. Also since you are watching the target it is easier to spot a low impact vs a high impact. If you are using a ballistic computer - you will begin to recognize a pattern of how that computer calls dope - is it typically high or low? Also how are you calculating distance? I have an LRF that goes to 1,200 (effectively more like 1,100), so when I am beyond this distance I am generally working off of GPS / Google Earth / Map / MIL reading - a 2% error at 1 mile means a lot in terms of dope on a 30"x19" target. Triple check the distance calc.
E) Use what is available to calc wind - I have used failing snow, rain, and even cloud movements. I shoot in mountainous areas and I know the wind is heavily influenced by the land features that I am shooting across or nearest. Thus I am interested in the action of the wind at the 1/2, 3/4's point, and at the target; but also nearest any significant land feature change near the path from shooting position and the target. Again - wind is akin to flowing water, visualize what water would do if it were to flow across the same land features that you are shooting across or nearest. Also, listen to the velocity changes of the wind as it pushes through the trees and grasses. Time the cycle of velocity changes. Note how the cycle changes during your shooting session. Study the wind pattern changes at various velocities. For example if you are shooting across a draw and the wind runs up it to the crest of a hill - at a lower velocity does the wind come up the draw and hit the crest only to boil back the opposite way at the top of the drawn? At a high velocity does the wind come up the draw and hit the crest and continue on in the same direction?
E) Understand and record predominate wind patterns in a given area and begin to recognize what land features generally have x effect on wind.
F) Worst case - like Greg said - bracket the shot.
Good luck