Its really just trial and error in finding what works for you. There is no single magic coil, there are many many great coils. So experiment, keep a log with all the data and your experience for each coil, and keep tweaking till you find the right combo.
First, BE SAFE!!!! The lower the resistance of your coils, the higher the amp draw on your batteries. Use a calculator such as
Ohm's law | Steam Engine | free vaping calculators. ex. a .5ohm coil at 4.2V (a freshly charged battery) would equal 8.4amp draw. If you drop the ohms, you increase the amp draw. If you exceed your batt max amp draw it could vent hot gases or explode. So know how many amps your battery can handle, and use the calc to be sure you will not exceed their limit.
If you use less wire by doing fewer wraps, or by making a smaller diameter coil you will decrease the ohms. You could also do dual coils; by adding a second coil you will reduce the overall resistance by 1/2. Getting more flavor and vapor could be achieved by lowering the resistance of your coils, but also by getting enough air-flow as well as getting the position of the air-holes just right. You generally want them as close to the coil as possible, either just beside or just below the coil.
I would play with the air-flow on your .5ohm coil before going lower. Use a liquid w/ more VG if you want bigger clouds. A 0.4-0.5ohm coil seems to be the sweet spot for me, though 0.4ohm is a bit on the warmer side.