1. Tune ADF
2. Turn up volume to hear you have NDB Station
3. Set heading accurately to where needle points
4. Fly heading
Sam that is the logical sequence but with a NDB you need to be bit more careful than that. I have known many cases were on the edge of range the needle is pointing but not to the beacon you want to get to, yet you can still hear the ident.
The first thing to be aware of is the protected range of the beacon(AIP) Never trust NDB bearings outside protected range or around thunderstorm activity and even then be very careful.
You also need to consider with some smaller airfields hours of operation as I have known some not to be 24 hour.
There is an old saying in flying that goes like this;
Never trust one man, one gauge, one engine or one instrument. I have seen the truth in it several times unfortunately.
On that basis I would need some type of duplicate or back up check that when the needle falls I am actually over the beacon I think I am. VOR check ATC etc etc.
You also need to monitor the ident throughout the approach if you are only using one ADF.
I worked with a pilot once who was based at an out of the way airfield with a public transport Aztec. He was returning one claggy night, went to the overhead and started the procedure, half way round he noticed the ADF had failed and there was no ident so diverted to another airfield. He subsequently found out that the barman at the club had heard an aircraft overhead and went and turned the NDB off. When later questioned he said that he had heard an aircraft overhead and thought. 'why should enroute aircraft use our airfield NDB', amazing but true, he of ,course never realised that Steve was about to let down on it as club flying had finished much earlier in the day and there had not been a movement all afternoon.