I think the points system should still be 10-6-4-3-2-1. However in this era when all the cars are super-reliable it would mean anyone who isn't in a Red Bull, Ferrari, Mercedes, Lotus or McLaren would struggle to get off the 0 mark.
I would like it if there was a one-point-per-placing system counting up from 20th place (1 point) to first (20 points) with the 90's 10-6-4-3-2-1 points added on top to incentivise finishing in the top positions. The result would be 30-25-22-20-18-16-14-13-12-11-10-9-8-7-6-5-4-3-2-1-0-0, and I would add 2 points each for pole and fastest lap to make drivers other than Vettel give it a crack in the final laps.
Classifications for drivers retirements within the last 10% of the race would be dropped so drivers only count as finished if they cross the line to take the flag, and every lap dropped to the leaders would reduce the number to be scored by one.
If in charge I would also make a few other changes...
1. A cap on the amount of downforce, enforced by mandatory wind tunnel tests and weight penalties added for cars producing too much at any one of a few selected test speeds.
2. Combine Q1-Q2 into one 30 minute session and replace Q3 with individual single lap runs for the top ten with an extra set of super-soft tyres provided for that one lap.
3. Change the race distance to two hours plus one more full lap.
4. De-restrict the engine formula, restrict it only by the maximum allotment of fuel for the race and make everything else (size, type, turbos, rotary, KERS) pretty well unrestricted - like it was for the glory days of Group C sports-racer cars.