I use two methods.

First uses a standard tapered leaded and an indicator that I can easily change the position of on the leader. I will sometimes use this method when I know I will be changing depth a lot.

Second is similar to a right angle nymphing system often used on streams. I use a short tapered leader (0x, 1x, or 2x usually) that is tied to a yard indicator with a clinch knot. My tippet is then tied on to the leader with an improved clinch not so it hangs off the tapered leader at a right angle. The knot is formed up against the clinch knot to the indicator. My tippet might range from two feet and up. The longest tippet I have used is 14 feet. This is the method I typically use for fishing midge pupa and larva on California's lake Crowley.

With the second method, you know your fly will be hanging straight down. With the first method, depending on where the indicator is on the leader, the fly may be shallower than the distanced between indicator and fly because the heavier tapered part of the leader arcs down slighthy rather than hanging straight down.