Anyone have any advice or techniques I can offer my students to improve their situational awareness during flight? Any practice-at-home techniques?
It varies drastically with scenarios. I will skim a few of them in an attempt to give some ideas.
General SA:
Stick & Rudder: As previously mentioned, these are a must. This includes proper use of visual cues, stick pressures, kinesthetics, sound, and even smell.
Practiced/Developed Procedures: This is an at home exercise as well as in the aircraft. Pick a task, develop a procedure, and then try the procedure. During the debrief, discuss the procedure and make any changes. Now take that procedure home and chair fly it. Do this with every procedure so the student can do them with as little brain power as possible.
Radios: Listen online at home to improve this skill. Tell the student to act as if they are one of the tail numbers and watch TV. Each time their tail number is called they should recognize it, even while watching TV. The TV acts as their distraction. Do this with an approach and tower frequency to learn the various phrases used. Reading the AIM can also assist with this.
Trim: See previous posts, always maintain trim. However, ensure they don't become trim flyers!
Emergency: Where would you land? Absolutely 100 percent, IMO, the most important piece of SA is knowing an off field landing site during any phase of flight. You should ask this randomly each and every flight. It takes 30 seconds when the student is doing it right and will likely save their life in an emergency.
Landing Environment
Configuration: What is our configuration? The response should be with an RPM, mixture, and flap setting at minimum. Asking this question a couple times throughout the approach, pattern, landing, and takeoff can help them to think about it on their own.
Micro Meteorology: I devote a lesson to this where we discuss basic of thermals, disturbed air over objects, wake/heli turbulence, and how it drifts with the air mass. Applying such knowledge, especially to the final approach, can really improve SA and keep the pilot thinking ahead. How many times do you see a student say, "OMG" when hitting lift or sink you already knew was coming? This shouldn't happen.
Cross Country
Points: This information was taken from the european training for XC navigation. Most instructors, myself included, teach students to pick a single point or maybe two as checkpoints on the XC. Here is another option and it provides impeccable SA if performed properly.
Large Point: Pick at least 2, preferably 3. Points should be large cities, bodies of water, or other general terrain features that can be observed easily from about 10-20 NM away. Use these points to get a general idea of your location on the sectional.
Small Points: Pick more than 2. These can be anything you fly over or near, usually within a couple miles of your route of flight. They include the typical points we teach students about as well as: power lines, roads, terrain features (hills/ridges/etc), water towers, airports, etc.
Handrails One of my students actually taught me this, an outdoor expedition leader. When you track to a point in the distance, you do so by selecting 2-3 points off your nose to make a line. Once you visualize that line look for points on either side of it to make a line on either side that runs parallel to your centerline. You are essentially building a roadway in the sky to follow, keep their head outside and off the DG. If you fly that road you will never go off course and can even see if your wind drift is working properly or not.
At Home: Tell the student to take 10-15 minutes with their sectional and follow the line with their finger. Look at all of the tiny details that they will fly over and attempt to visualize what it might look like when they are flying. A good 15 minutes of this can do wonders for their SA when they do the XC.
One final thought, during any approach to pattern, maneuvering for a field, setting up for ground reference, etc. Have the student pick a ground track they wish to fly to do it. Imagining how that ground track relates to the airport and will bring them back to set up for the 45 entry might save you that, "hey where did the airport go" question we almost always encounter with our students. Assessing how they move over the ground can also help them assess the winds a loft.
So you see, SA isn't so much a simple do this and it works. It is a complex network of various little tasks that add up to a detailed image. Hope this helps and good luck!