@swales87 This is probably a bit lengthy (get the

!) but hopefully it mentions a few new tips and puts your question to bed, satisfied!
{If a moderator deems this more appropriate elsewhere after it has done it's job here feel free to move it!}
To reinforce DHL & Wevskys advice it is not a good idea to go in any of them if you rely on temporary markers like glow sticks only. As I posted on Trog's report '
Northamptonshire Ironstone Mines June-Aug 2010': I go well equipped with food & drink, spare kit etc)[as DHL says: for emergency scenarios lasting 12 hours+] never alone (3 if possible) & always phone ourselves in with a 'due back' time & intended route of exploration with another friend ... and
call them back when you're out!
Before I became 'confident' with them or had mine plans, I used to rely mostly on drawing my own map (noting magnetic north) on a grid paper clipboard as I walked, marking turns I walked past and ones I took & noting any distinguishing 'landmark'. That way I could not confuse my route markers with other explorers (unlike wooden arrows, tinfoil etc). Don't forget, others might be down there at the same time as you, so please do not move other markers to use as your own & remember somebody may remove their own marker on their way out - which is not good if you rely on it still being there! I also disciplined myself to walk in a set way (mainly in straight lines through crossroads and turn only at T junctions), with a tiny arrow of soluble chalk at a set height on the wall (if necessary) to double confirm the way I came from after any change of direction.
My key bit of advice:
Even if you acquire a mine plan (with a compass to orientate), do not rely fully on them & (again) I recommend marking your route on the plan as you go. They are abandonment plans & not "up to date" plans. This means roof cave-ins can block paths/junctions and most significantly, many tunnels were bricked up for ventilation purposes meaning you can find your way into a large section of mine and need to find the same single path out which may be a long way in the opposite direction to your intended destination. This isn't much of a problem if you have time but if you are experiencing bad air and need to get out with haste you do not want to be trial and error exploring all avenues shown as open on the plan for the real open one.
Discuss your route and map as you go with the others if they do not have their own.
Getting lost
It is inevitable at some point exploring, no matter how prepared, you will have a sphincter clenching moment and believe yourself lost.

You may just be holding the map at the wrong orientation for that split second or be one junction away from your last marker/landmark. So have an arrangement to take a seat, calm down and discuss your thoughts of location with the others (where 3 brains is better than 2) before methodically walking a short way in all directions to locate familiar ground and return to your seating to discuss the most promising before venturing off, rather than walking miles in one guessed direction, hoping. Please for all our sakes do not run around in an uncoordinated panic - you dramatically increase your risks of getting in a worse situation and the rest of us discovering you as an 'historical artifact' at a later date which will close the mines.
Lastly
Don't underestimate the scale of these mines and scope for error. As I discussed with Troglodyte, from the mine plan my calculated estimate was that Church has 8400 chains, (
105 miles) of excavation.

Church is not the largest of the Northamptonshire ones either.