If I have a 5x leader, can I only use 5x tippets or can I use 4x or 6x? If not am I supposed to change my leader every time I change from a size 12 to size 18?

Idk what you're supposed to do, but I mix and match leader and tippet all the time. I'll use different tippet sizes together as well. I've read that you should use a lighter leader/tippet(6 or 7) for dries, little stronger for nymphs(4 or 5), and heaviest for streamers( 3 or 4). Of course there are half sizes and length of leader/tippet varies greatly depending on depth, rod weight, fly pattern, and skill level.

Lately I've gotten into the Trout Hunter brand of tippet and leaders. It's pretty tough stuff. I also tend to use fluorocarbon.

You CAN use 4x tippet on a 5x leader it just might not turn over as well. Just keep the tippet short & you should be ok.

If it is a new 9' 5x leader, cut about 1.5 ft from the tippet end and tie in your 4x tippet if that's what size you need to use. What you want in your leader is for it to taper down. Thickest at the butt section and thinnest at the fly.

What I used to do is put on a 4x leader then add 5x tippet. When slinging smaller flies, I would just add smaller tippet to the end as needed. As long as you keep the taper stepping down you will be fine.

i'd suggest getting some tippet rings, it makes connecting the tippet and leader so easy and keeps you from having to cut pieces from your leader off

 

i'd suggest getting some tippet rings, it makes connecting the tippet and leader so easy and keeps you from having to cut pieces from your leader off

 

 

 

Tippet rings are differently the way to go.  I have many leader set up depending on how i will fish that day.  From high sticking with a sighter in the leader to my 6x dry fly leader.  At the tippet ring you can change out your different set ups.  3x to 4x or 5x to 6x.  it makes changing leaders fast and easy if you prep before you get on the water.   

Tippet rings are differently the way to go.  I have many leader set up depending on how i will fish that day.  From high sticking with a sighter in the leader to my 6x dry fly leader.  At the tippet ring you can change out your different set ups.  3x to 4x or 5x to 6x.  it makes changing leaders fast and easy if you prep before you get on the water.   

i picked up some rig spools from Loon the other day.  I've prerigged a few setups so I could change my setup quickly.

the rule of thumb is you don't want your tippet to be larger than the leader.  that also isn't by number but by size of the actual material.  On a new tapered leader i will just go down one size for my first addition of leader material and then as i lose tippet and/or leader i will match up sizes and rebuild the leader as I go along.  For the most part though, i have switched over to straight leaders, especially for bass fishing, and i haven't seen a drop in performance or ability to cast.  if i know i am fishing a small mountain stream, i will go to a tapered leader though as they do roll cast a little better in tight quarters.