how do you safely use jack stands?

Ok, I grew up working on cars. But I grew up kind of spoiled and my dad had a really nice shop with an in ground hoist. I never had to use a jack and jack stands. So, now I have my own place and a barn but no lift. I have to work on my car with jack stands. I always feel like the car is going to fall on me when working on it.

When lifting my car from the front, I always put my parking brake on and put those wheel things behind the wheels to stop my car from rolling back. Then I jack up my car and then put jack stands under the sub frame in the front (the spot I'd normally put the hoist on to lift the car. Looks like a frame, but it's a newer car so it's a sub frame for the front.)

What I don't like about doing this is because my car is on a 35 or so degree angle, back tires on the ground, the angle between the jack stands and the car is not 90 degrees so I know there's more weight on the back two feet of the jack stand than the front two feet of the jack stand, which makes me nervous. I'd like to leave the jack under the car too to act as a backup in case the jack stands fall, but putting both jack stands and the jack under the car leaves no room to work.

So, it's stable but it makes me nervous when I'm under the car with big wrenches reefing on things when I know those stands are not probably 100% stable.

So, wondering what other's thoughts are on this...

Certainly a legitimate concern. Usually when I do it, I usuall stuff the tire & rim under the edge of the car just below the front wheel well (where the lift point/pinch welds are on some cars). If I can't do that, because the jack stand is at the pinch weld (rather than on the subframe), I usually will lift the rear end as well, and put jack stands down there was well. That way the car is level, and feels far more stable (I usually slide the rims under all 4 corners anyways). Other than that, I just try to get under the car as little as possible, and get it done as quickly as possible.