When you are new it is better to start with drops to get some feeling how it works.
I have been on maintenance for many years and stick with vertical drops, if you want more do the horizontal drop.
From an old post:
Lugol's is a liquid. Drops can be added to water, juice, soup, wine or scotch and drunk.
The correct way to make a drop of Lugol's is to hold the dropper vertical and squeeze the rubber topper. Each vertical drop is 6.25 mg of iodine. Then you can do the math by counting the drops.
Horizontal drops - with the dropper held side to side are twice as much - 12.5 mg Iodine per drop. How do we know? We measured, a couple times. Why?? Because some of us wanted to know how many drops of Iodine are in an ounce bottle.
Several of us found out then that we were taking twice the amount of Iodine that we thought - because we were using horizontal drops.