How long of Floro leader do ya all use when fishing this set up on Texas rig or football jig?

I like about a 6 foot leader, as long as the connecting knot does not go into the reel I am fine with it.

This ^^

It give you more chances to retie before you need to replace the leader. I think it's less likely to snap on the hook set when it's longer too. I would recommend using 20# fluoro leader for football head or t-rig. You probably don't want to go less than 17#.

What kind of knot are y'all tying? When I tie my alberto knot, it seems to catch on the last eye so I keep my leader short enough that I can flip without having to reel that knot in past the last eye.

I use a double uni.

For bait casters I usually do 4-6', on spinning reels I go 10-12' allowing the knot to pull into the reel. Mostly b/c it doesnt effect casting and I can retie often without having to retie the leader.

I learned the FG knot and have not looked back since. You can make the leader 6-7' and it won't get into the reel and casts right through the eyelets like it wasn't even there. Takes a while to learn but worth it!

Double Uni / uni to uni

FG knot is the way to go. Goes through the guides without a problem while casting so you can use a nice long leader. Here's and instruction video.
https://www.youtube.com/watch?v=R0kHbVdXkk8

+1. If you will learn to tie the FG Knot, you will be amazed at the difference between that and double uni. I was using double uni but didn't like the way it was passing through my guides. If there is a thinner knot than the FG, I would like to know about it.

The FG takes some time to tie, so I do that before I go to the lake. Leader probably 10 feet long so plenty of re-tying before it gets too short.

I use a 6' leader and I love the FG knot for all the reasons stated above. The only drawback for me is I find it hard to tie while in the boat in those rare cases where I must re-tie during the day. That is when I fall back to my 2nd most favored knot "The Surgeon's Knot". I used this exclusively for years until I found the FG. For me the surgeon's knot is probably the easiest of all knots to tie, is incredibly strong and will travel through guides almost as easily as the FG.

FG knot if I'm tying it at home. Uni to Uni if I'm tying it on the boat. Also I've noticed that the FG knot only works if your leader line is larger than your main line. The braid "digs in" to the leader line so the leader line needs to be thicker. I've never successfully tied the knot using small (6-8lb) leader line