An instrument approach is the cats meow. If flown correctly it can put you right on the numbers every time. Note the if. Well what is required? For starters having the data to fly the approach. These can be obtained from various sources. My favorite was Jeppesen. A bit pricey but loaded with the info you need in a readable format.
OK, so now you have the charts out you must look them over. If there is an ATIS on the field, listen to it in plenty of time to get all the pertinent data: wind, ceiling and active runway. This will allow you to select the best approach for the weather/runway. If you don't need the ILS because of a high ceiling maybe the VOR will do and save you some time. This of course depends on the specifics. Sometimes the ILS can be the simplest depending on factors such as traffic.
Say for example we choose the ILS, the most precise, it is time to study the details of the approach. These include altitude at the initial segment, inbound heading and minimum descent altitude. The MDA is critical, busting minimums is not a viable option. It is pertinent here to say that if this approach is to be flown outside the radar environ without approach control guidance, the ball will rest squarely in your court. Now you will be dropped off by center and "cleared for approach" all on your own. Before I offer a check list for performing an approach I should add that you should glance at the missed approach procedure, especially in the non radar setting.
All right so far? Now let's break up the approach into three segments
1. Enroute to the FAF
Set radios, confirm correct freq. with audio
Maintain position awareness (know where you are on the approach-there may be high terrain nearby or even a restricted area).
Crosscheck data with your DME, GPS, ADF
Approach flaps and ready for gear down
Fuel on mains (usually)
Check autopilot on if using a coupled approach
2. Final approach fix
Cross check altitude vs. GS if on ILS
Especially if on A/P
Call out altitudes every 500 ft (yes, even if flying solo)
Review minimums and missed proc.
3. Landing Assured (runway in sight and free of traffic)
Final gear check
Disconnect A/P if used
That's it in a nutshell. Follow these guidelines or something of your own doing, BUT do have a procedure for insuring that you cover all your bases, and you will have a good safe approach and happy ending to your flight.