I had a lot of trouble landing when I was at your stage, and had this cured by an observant instructor, who suggested I sit on a cushion. Onya Nick!
Here's some tips from someone with a few thousand hours of teaching people to land various types of Cherokees.
1. Follow the POH, the guys that wrote it know best, and that is what the insurance company will go by when deciding whether or not you have been negligent or just unlucky in the event of a landing accident. 65 kts is the correct approach speed with full flap in the Warrior.
2. Where to focus...about 10deg above the horizon is good once you are over the numbers. Right through the touch and go. Humans have huge amounts of peripheral vision which you can use to judge height and speed. Don't focus onto the runway or you simply can't judge these things.
3. Don't chase the needles, learn to do the approach by the attitude and feel of the controls, and then use the ASI to confirm that you are trimmed correctly. Then one day if a bee decides to commit suicide in your pitot tube you will have no worries.
4. In the flare forget the ASI, use enough back pressure to keep the gap between the nose and the end of the runway constant. Focus up! About 2 inches workes for me at my height, but this varies with individuals. You are not raising the nose rather than lowering the tail, think back to stalling and the gradual back movement of the control column. That's what you are aiming to achieve when you land. And that is where correct seat height is essential, in my case I couldn't maintain that gap because all I could see in the flare was a facefull of instruments, and I'm not that little, 5 foot 8. One cushion saved my career when I was ready to give up!
5. Don't try too hard. Let the aeroplane land in its own good time. Many students try to "force" it onto the ground, often this is accompanied by a rapid relaxation of the back pressure when the wheels touch the ground (a big no-no). If there's not much runway left, go around.
6. Keep it straight with rudder.
7. Keep it straight and keep the focus up.
8. Keep it straight. It's just as easy to land on the centrline than anywhere else on the runway, and much safer.
9. Keep that focus up right through the touch and go.
10. Applying power in the flare can lead to a marked yaw left. and can take the inexperienced unawares. Not needed in the Warrior. Ever noticed that people always run off the runway to the left in aircraft with props that rotate clockwise from cockpit? Keep it straight!
11. Watch the experts. Seagulls are easy to observe because they seem to land in slow motion. In the absence of seagulls, ducks make good flying instructors too.
Good luck!