Great questions! This is how we learn and I commend you for pursuing the answers to questions you have.
A couple of questions with fairly simple answers.
Quote: "When I was fishing and tying on different flies, my leader line right before the fly would become curvy, or not straight and clean. This looked bad in the water and may of spooked some browns. My question is is this bad? And if so what could be the cause of this?
Short answer, yes, it is bad. The "curly cues" are caused usually by tightening down your tippet knot too fast without proper lubrication. As the knot constricts it generates a tremendous amount of heat which in turn causes damage to the material and weakens the knot. If you remember how you lost flies while casting? If your tippet knots were tied as you just described then the "buggy whip" didn't require much force to pop those flies off. Also, when hooking and playing a fish, with the tippet damaged you have greatly reduced the tensile breaking point of the line and most fish hooked under those circumstances will usually break off, taking the fly with them.
Whenever I tie a knot to attach my fly I will always take the knot to my mouth to add a little saliva as lubrication. If you're concerned with water-borne bugs, then wet your fingers and slather the knot with the water or just dip the fly and knot in the water just prior to cinching it down tight. Don't do it too fast, just make a fluid motion to cinch it up.
Quote: "I was also wondering when should you start adding tippet to your leader?
This is almost sacred ground for some, but here is a quick and easy solution that I use. When buying your new tapered leaders, buy ones designed for the type of fishing you are doing, trout fishing in your case. Then make sure to buy leaders that end in 2x or 3x. Tie a Perfection Loop in the end of the tippet (Orvis_Knots
) . Then, take an 8 to 12-inch piece of tippet material in either 4x or 5x and tie another Perfection Loop in this material, then attach the tippet to the leader using the two loops in a loop-to-loop connection. If dry fly fishing start with 4x and add another piece of 5x to the 4x for a finer tippet for smaller flies. For nymphing, and, if using split shot to get your nymphs down, then you can attach those above the loop-to-loop connection (learn how to remove them or use removable split shot to start with). When you have fished enough and changed flies several times to where the tippet section is around 6-inches or shorter, just remove that section and discard (make sure you save the discarded material for later disposal and not drop it in the river) now you can re-tie a new section as described above. In most cases you then should be able to use a regular nylon tapered leader for a minimum of a half-season if not for the entire season without the need to keep adding tippet to a diminishing leader butt.
That's how I've done it and it seems to work, yet I know there are many opinions on this one, so pay attention and choose the one that makes the most sense to you.