The Aviation Mentor blog (what, you mean you don't have this fantastic blog set up in your mandatory reading list?) had a great post on VTF or WTF? He was bemoaning the fact that many pilots when they hear the controller tell them "Fly heading 180, vectors for the ILS 19R," they will automatically load the approach and select Vectors To Final when being presented with the approaches transition options.
The biggest problem with this that as soon as you do so, the approach controller will invariably tell you something like "three miles to SNAKE, cross SNAKE at or above 4000 feet, cleared ILS 16R" and then you're stuck trying to change the procedure at the last minute which can be stressful and take attention away from what you are doing.
I had this happen a few times in training and I since learned to load a full-approach but this method of extending the centerline of the final approach course is quick and easy. Since I fly behind a pair of GNS430s, the G1000 section at the top of his post wasn't of as much interest to me as the following:
To get the intermediate fixes to display the Garmin 530 or 430, the sequence is a bit different. For this example, let's consider the Salt Lake City ILS RWY 16R, which has three intermediate fixes outside the FAF.

Load the approach with OGD or FANDS as the transition: It doesn't really matter which one you choose.

Activate the approach and you'll be dumped into the flight plan view. Press the small knob to enter cursor mode, scroll with the big knob and highlight BNKER (the FAF), then press MENU.

The Activate Leg option is highlighted by default, so press ENT twice.

This view gives you pretty much what you need, but if you want to see the magenta line extended out farther, there are a couple more steps.

First, make sure your OBS or HSI is set to the localizer front course.

Next, press the OBS button and you'll see the magenta line extended outward. Small problem, the intermediate fixes have disappeared.

Press the OBS button again and like magician David Copperfield, you've reversed the disappearing act and the IFs are shown again.
