1. Mark the crap outta your cards.
I made my cards out of a heavy tagboard (not posterboard - this stuff is about twice as thick) and then marked them ALLLLL up. The card on top is the side that faces left, and you'll see that's numbered in black. If I'm threading in the S or \ direction, the threads go through from that side of the card.
The bottom card is numbered in orange, and for some reason I wrote CC on it. I can't for the life of me figure out what CC was supposed to stand for. Anyway, this is the side of the card that faces right, and if you are threading in the Z or / direction, your threads go through that side.
Notice that the holes are lettered clockwise on the S side, and counterclockwise on the Z side, so each hole has the same letter on both sides.
Also, you can't see it, but the edge of the cards on the A-D side have been colored red. This marks my "home" position. It's where I start from, and once all the cards are sitting with the red side up, I know I've gone through a complete pattern sequence. It is handy - trust me. Having that particular marker makes it a lot easier to un-weave or find your place in the sequence. You could get even fancier and mark each edge a different color - just be sure you remember which color is "home".
Oh, speaking of making cards - definitely DO make use of scrapbooking supplies to make yours. Using a round corner punch on all your cards is way faster than rounding off by hand, and you do not want to leave square corners, especially if you will be working with fine threads. Corners catch threads.
2. If you're working on an inkle loom, warp in a loop directly on the loom.
(I apologize for not having snapped a picture at this point.)
When you're doing card weaving on an inkle loom, you're basically working in a loop. You weave a section, loosen the tension, then slide your work out of the way which exposes more unworked warp in your work space. Tighten everything back up, and you're good to go.
When I warp up my inkle loom, I try to work it out so I have a good 8-12 inches of extra warp length, which will get taken up by knots and end-cutting. I warp in sorta-kinda continuous loops, switching colors according to my thread-up pattern as I go. This means that I sometimes have knots at the peg where I start and stop my warp circuit.
So once I'm done looping on the warp, I use cloth athletic tape or masking tape to tape the warp to my uppermost pegs so the whole lot doesn't fall off. Then I CUT THE WARP. One cut in front of my start peg, and one cut behind it to even everything up.
Once it's cut, I thread up my cards on the bit dangling right in front of me, and redistribute the remaining warp around the rest of the pegs to give me the slack I need to tie the ends together.
But don't tie them ALL together.
3. If working on an inkle loom, tie your edge card warps together separately from the rest of the warp.
This is because...
4. Always turn your edge cards on one direction only, and turn them every pick (pass of the shuttle / weft.)
This is probably the single thing that will improve the look of your weaving the most.
You'll notice, when you are weaving patterns that switch the direction you turn the cards, that you get lumpy weirdness in your selvedges whenever the cards reverse direction. And if you work with split-deck patterns, where the edge cards might only get turned every other pick, you end up with loose selvedges that don't pull up to an even width.
Turning the first and last card in the same direction every single pick will solve all of that. You'll get a nice, tight, even selvedge that looks professional and smooth.
The reason tying up your edge cards separately is so important is because turning in one direction every time builds up way more twist than most patterns do, and those cards of threads will tighten up considerably more than the rest. You'll want to be able to untie them periodically to release the built-up twist, and it's much easier to do two cards' worth than the whole bundle.
5. Follow these steps to get an even width and tight selvedge.
Weave a few picks to get started. Now, when you pass your shuttle through, don't pull your weft thread all the way through. Leave a little loop sticking off the side.
Now turn your cards as indicated by your pattern for the next pick. Use your beater or edged shuttle to pack in your weft...
...then pull the weft thread to close the loop on the side. Pull it tight enough to draw the band edge together smoothly, without making a divot in the edge.
Then pass the shuttle the rest of the way through, being sure to leave that loop on the edge again.
If you do this every time, you'll get a feel for what tension you need to apply to get a consistent width on your band.
6. Try not to slide your cards too much.
I was going to recommend sliding your cards back and forth on the weft after turning, to open the shed (the space between the top threads and bottom threads that you pass the shuttle through) but....well, that's only a good plan for tough, tightly woven yarns. As I was working with the 3-ply linen thread in these pictures, I discovered that sliding the cards was wearing right through ply threads in my linen yarn and causing breakages.
So, to avoid that, just stick two fingers into the shed right up against the cards. Open up your fingers like scissors, and the threads will separate to define your shed.
Hope these tips can help someone step their game up to the next level. Happy weaving!