As an owner and user of a sub-100 mile EV, a Fiat 500e, where inefficiency can literally leave you stuck on the side of the road, I mostly concur with the assessment below.
Other than driving slow, they're not helping.
You don't need to slow going up hills. Speeding up going down hills might save energy if speeding up didn't also add air resistance. Moderatly aggressive acceleration is fine, too.
Efficiency isn't always measured in mi/kwh. We're already winning because every EV is tons more efficient than an equivalent gasmobile. It's why the Bolt can get over 220 miles of range with a battery that is the equivalent of less than 2 gallons of gas. So modulating hills really isn't going to significantly change that. As others have pointed out, the #2
source of consumption after speed is climate controls, especially resistance heating. AC isn't awful, but it does cut into the power budget a bit.
On the freeway, go with the flow, drive behind another vehicle at whatever speed. Big SUV or truck will work well. You can still be at a reasonable following distance. Driving 70 mph behind someone is probably better than driving 65 mph with everyone passing you.
This is the only point I have a disagreement with. When I know I'm going somewhere that's going to require a recharge while out, I set the cruise on the highway to 60 MPH and drive in the far right lane regardless of traffic flow. 65,70,75 MPH or higher cuts into the power budget by a significant margin. Personally I find that using big trucks as a buffer by riding in front of them offers the most protection from the zoom zoomers.
The following point is the most crucial one.
For modest-sized trips that aren't pushing the limits of the battery, best to just drive however the mood suits you and enjoy the car.
Driving normally is the best revenge. Unless I know I'm going a route where efficiency is crucial, I never worry about it. I know in non-winter seasons that my full commute is less than 50% of the battery driving normally. With that much to spare, it's not worth bothering trying to modulate efficiency. Like I said, we're all already winning.
If you need to stop and charge, mostly you can drive as fast as you like. Driving faster uses more power, but it's still a win after factoring in added charging time (assuming a decent-speed DCFC station).
In my situation with L2 only, I actually have to use destination timeframes to make that decision. If I'm parking at a charging station for a couple of hours or more, I don't worry about it. However, if time is a factor, typically I'll slow down driving to the destination to conserve electrons as the further I dip down the SOC curve, the longer I have to sit at the charging station to recoup the energy to get back. But honestly, if I had a DCFC capable EV, and knew that there was a decent speed DCFC station along the route, it would be a worry free situation as far as I was concerned.