I am hoping someone can give me some advice/tips on how to solve this problem...
 
For quite some time the indicators on my Mk2 RS2000 would have moments when the indicators would flash very fast (generally when car was hot). I know this is commonly a sign that a bulb has blown, but all bulbs were and still are ok. I just let it go because for the amount of km's I did in the car it didn't really worry me. Unfortunately now though, the indicators are not working at all. I thought perhaps flasher unit had died, so replaced that, but this did not fix the problem. The hazards still flash normally but trying to use the indicators just results in a extremely fast ticking of buzzing noise being emitted from the flasher unit, but no lights.
 
I am thinking that the next step is to start looking at the indicator stalk but would like any advice or opinions and possible things to look out for.

My indicator issues have always been bad earths at the light ends.

As PaulMKI said, check all the grounds to the indicators. 
 
Also check the bulbs are fitted properly in the dash itself.  I have had a few issues over the years with the bulbs not connecting properly and hence the indicators won't work.
 
If you have one of those power tester needle things ($10.00 from Super Crap Auto) just work your way along the wires to see where the issue is.
 
Good luck
 
Matt

Your indicator stalk is knackered.
There is only one flasher unit and if everything works when the hazard switch is on it can only be one thing.

As fordsy said, it's the stalk. Most likely to find a broken wire joint/solder. Can be fixed if you're handy with fine soldering. This will be a common issue with many people using the non OE stalks now, but then again, there's not much choice for us.

After all that it rurned out just to be the fuse connection. I removed the fuse box and just fiddled around with all the wiring, making sure everything was connected properly (it looked like it was anyway). Then put it back together and gave the indicator fuse another wiggle for good measure and indicators decided to start working!
 
The car can now go on it's bi-annual outing and I now have spare brand new flasher unit.
 
Actually, funny story. After getting the indicators working and then cleaning the car today I was searching through the glovebox and found..... another spare flasher unit, which I bought about 10 years ago. I obviously didn't remember this, but I probably went through the same scenario 10 years ago. By that logic, I should have 3 spare brand new flasher units by 2021...
 
Thanks for the advice/suggestions guys.

Oh the joys of classic motoring - seemingly so simple but always so frustrating!

Dont worry guys, when I was last in the UK I managed to get hold of a large bag of FoMoCo wiring loom smoke, so if anyones loom leaks out some smoke, I have some to refil your loom.
I also have a bag of Lucas (the prince of darkness) Smoke for Leyland looms, which is in another shed, cos as everyone knows, you should never mix or blend the two.