I definitely recommend the Drop as well. I would recommend getting some 24, 26, and 28 gauge wire. Those are the norm in most cases. Get yourself one of those coil master coiling jigs. Cotton Bacon is also a good cotton.
I build for a specific wattage. You need to know the formulas
V = IR
P = IV
Say it out loud, "PIV" and "VIR." I = current(Amps), R = resistance(Ohms), P = power(watts), V = voltage.
3.5V is the standard voltage people calculate for. So I know I want 25 watts so I will use P = IV. I solve for I(current). P/V = I. 25/3.5 = 7.14Amps. Now I use V=IR. and solve for R.
3.5/7.14 = 0.49 ohms. So I would look it up on a calculator and see what I need to build a 0.49-ohm coil. This is how I do it, others do it differently. Some focus on Voltage, some focus on amps, some focus on resistance, some focus on watts.