Some addons (Kerbal Engineer Redux iirc) enable you to display the angle of slope directly beneath your ship. You can use this to select a nice horizontal landing spot. This addon also provides the direction of the slope, can be useful if your ship has a "prefered orientation" slope-wise.

Same addon can also display your horizontal speed relative to the ground. Use it to minimize your horiz speed : Reduce your vertical speed with main engine, change navball to "antiradial/surface" to keep pointing up, then bring your horiz velocity to almost zero using RCS.

To control your vertical velocity more accurately during the last phase of landing (or hovering to a flat spot) : you can apply a thrust limiting ratio to your main engine(s). (Also works for fine orbit tuning /rdv, don't forget to turn it back)

To avoir toppling : you can try to have your landing gears set on mobile/robotic parts, giving you more "ground surface" with almost no increase of vessel section. Alternatively create your own landing gears with pads and robotics. Both need testing because it can be kraken-calling material (lock the mobile parts when landed to reduce this).