ornate wasp
I don't get it. Every time I try to build a realistic plane, the center of lift does this. Why does this keep happening? Is there a way to have this not happen? My planes always flip because of this. I just want to build a proper tailfin. Also, even when the CoL and CoM are in the right spots, I find planes never seem to turn correctly? Am I doing something wrong?
odd hare
i believe you may have difficulty turning because the control surfaces on your tail stabilizers may be enabled
you likely don't need them to be so large either, small ones do just fine.
naive mist
You could try giving the wings a small angle of attack to increase their contribution to lift. And yeah, make sure you set each control surface’s actuation toggle for a single axis
sterile niche
Define “trying to flip”- it keeps pitching uncontrollably to go tail-first?
Real airliners have adjustable stabilisers that can change their pitch to trim the plane depending on the weight distribution, but you can’t do this in KSP easily and the relatively small control surfaces on your tail plane will make it much harder to control the pitch and yaw.
Try using a larger fin or building your own with several elevons which can be adjusted independently for trim. Keeping the fuel in the centre, in the wings and the fuselage between the wings, will minimise any movement of the CoM as fuel is burnt.
ornate wasp
Update:
I got it to fly
I missed your suggestions because I didn't realize you responded
However, it flies like shit
I had to angle the engines down so it didn't uncontrollably pitch up and spin out. It also turns super bad and I have to yank the controls hard to get it to sorta kinda turn
Control settings: Each tab is for the surface closest
Left to right - first is for outer wing flap, second for the one right next to the airbrake, third for the one over the engine.
First winglet is the horizontal tail stabilizer, second is the tailfin.
@sterile niche
sterile niche
Try rotating the horizontal stabilisers so they have a positive angle of attack, leading edge higher. This will create a nose-down effect that should counteract the instability, but it will vary depending on airspeed. Try using the trim settings (alt + pitch up/down) or if all else fails there's the Atmospheric Autopilot mod that can make even the most unstable planes reasonably flyable.
There's no point having pitch controls enabled on main wing control surfaces, they're right on top of the CoM and CoL so will have almost zero effect other than adding drag.
I would also suggest moving the engines up and forward, 737 style, so the centre of thrust is closer to the CoM.
ornate wasp
Try rotating the horizontal stabilisers so they have a positive angle of attack,...
Like this?
That moves the CoL even farther back 
I don't know why
sterile niche
CoL takes wing angle into consideration, you might want to try a degree or two of angle on the main wing, again leading edge higher. KSP aero physics only works based on angle of attack against the airflow so a small angle on the wings means they'll produce lift on the runway, making it easier to lift off.
