Leading edge devices to make a better gliding wing?
Until Boeing changes their manual a clean wing is your best L/D for gliding.
Leading edge devices have a huge reduction in stall speed. The first notch of flaps is typically about 50% of the total stall reduction you get from flap extension.
1. Fly the airplane. Airspeed towards target dual engine failure speed. Evaluate energy available(altitude and speed).
2. Try engine restart or any other immediate action steps.
3. While attempting #2 continue with plan of action, which right now, with no engines means to head towards landing area. - 1. runway 2. clear ashpalt/concrete 3. smooth open land 4. water 5. best available
4. Get as much done as possible. Checklist or wing it, your choice if time is very critical.
If you can't start the engines, immediate action items are done, radio calls are made, I'd notice the crew or passengers.
Bleeds? Packs? Outflow valves? This accident shows how those are nice to do things, but not necessary in a time critical situation.