this Guide is curtsy of Gary1701 from BM
where the B1192 runs North to South directly against the fence of RAF Coningsby at that end. There's a layby directly against this fence where you can get probably 6-8 cars in at a push. Aircraft landing from the East (as in Marks pics) will land right over this road. You don't need a long DSLR lens for this as you can just walk up towards the landing lights alongside the road (have to be careful as it's a straight and fast road with not much of a grass verge) and photograph as close as you like.
Also, just around from the layby on the South Eastern corner of the airfield is a farmers field in which the local farmers appear to have no problem with people walking down to be beside the fence. The taxiway from the Southern HAS sites is right up against that fence at that point and some very close up pictures can be taken as they come out. They will usually hold short here directly infront of you. There is the usual tall barbed wire topped fence at this point but many photographers just take step ladders and shoot over the fence. Example linked below was taken on a DSLR camera, but only with a 28-135 lens fitted - they are very close. Again, there's no issues with doing this and you will often get a friendly wave from the crews as they taxi past.http://www.airliners.net/photo/UK---Air/Eu...hoon/2031094/L/
Usually you get a wind out of the West, so they'll land and take off from the Eastern end (runway 25) but you can go up the other end if they are working with a Easterly wind. If you're at the Eastern end then the already mentioned Dogdyke Lane runs from one end of the airfield to the other, and is just to the South of the airfield. It runs from the village of New York (less than a mile South of the Airfield on the B1192) right to the Western end of the airfield, turns North on the corner, and then runs alongside the Western end of the airfield. Here you'll find the landing lights at the Western end, the car park just beside here on the Northern side of the lights, and further up you can see the main Apron where the Typhoons flown by 29®, 17® and the Tornado's of 41® Sqn are operated from. The BBMF hangar is the one right against the fence here and anything from them flying will be parked within a stones throw from the fence. The Spit below is again from the step ladder as it's again a high fence but can be photographed over. Same lens as above - the Typhoon behind is on the main apron already mentioned. Sunlight will only be behind you here late in the day.http://www.airliners.net/photo/UK---Air/Su...fire/1721672/L/
If they are landing/departing from the Western end you have two options. Either park in the car park that is just on the Northern side of the landing lights and walk down the road to the other side to get the sun behind you, or just on that South Western corner of the airfield is a small entrance to a piece of waste ground and a earth mound that many photographers use for a elevated view across the 07 threshold. To take pics from this location you will need a longish lens in the 200-250mm range for a Typhoon sized aircraft. This is again a local farmers property but there's plenty of room to park beside the mound and as long nobody blocks the track in they seem perfectly happy for people to go there. Another example from this location below, also shows the BBMF hangar behind with the two Spit's infront and the Typhoon line on the apron.http://www.airliners.net/photo/USA---Air/M...-15E/1721764/L/
You can also put a stepladder up beside the fence on the Western end and photograph aircraft at close range taxiing between the 07 threshold and the main apron. The Rafale linked below was taxiing from the apron to the runway. You can only get the light behind you here late in the day.http://www.airliners.net/photo/France---Ai...le-B/1732377/L/
If feeling adventurous you can take your step ladder further down and set up directly inline with the main runway and photograph aircraft as they taxi off towards you. Only do this when they are landing from the 25 end, not landing over you at the same end or the base will not be impressed and will send somebody out to have a word - there's a reason that fence that you're now above has been replaced several times! Again, only works late in the day and sometimes aircraft will turn off short onto the old cross runway and take a short cut back to the apron. If you can catch a Typhoon still with the foreplanes rotated it makes a good shot here;http://www.airliners.net/photo/UK---Air/Eu...hoon/1562286/L/
There is a gate and fence on the Northside that looks across the taxiway on that side, you would need to go into Coningsby town, turn and go past the main gate to get here, but because it faces the sun for most of the day I rarely go there.
Monday to Friday is normally quite busy, although it usually tails off quite early on a friday afternoon. You tend find they will launch early/mid morning and recover late morning, repeating the same pattern in the afternoon, sometimes with a late and early afternoon wave. There can sometimes be a lull over lunch, although that can be covered by circuit traffic from elsewhere. If it's a week when they're working 'nights', then they will usually knock the morning sorties on the head and start late. Having a look at the number of aircraft on the main apron can be a good guide.
Hope that helps anybody heading that way.