Dimension your lumber. I left mine rough sized as I plan on trimming and planing it once the glue up is done.

The method we're going to use to make sure we get a good level glue up is called match planing. First layout the pieces on a work surface to get the grain direction and general layout of what you want. Once you figure out what you want, draw a triangle across the boards so you'll know how you wanted them to be lined up. (I forgot to take pictures of this part). Once you get the markings and layout done, flip the 2 pieces where the ends to glue up and next to each other. Think of the layout as a book on the table, and you pick up from the middle and bring the edges to glue up together.

The beauty in match planing is that even if your plane technique isn't great, or your plane iron is a little skewed - the angles will cancel each other out on the two pieces since you're doing them together. You don't need a #7/#8 here, but a longer plane does help to ensure you're getting a flat edge and is recommended.

One of the boards is relatively square on edge, and I'm already starting to get full width shavings on that one. The other one isn't square or flat, so a couple more passes will be needed.

That's better. Keep going until you get full width shavings from both pieces, from start to end. There is also a technique called a "spring edge" or "sprung joint" that can be used if desired. I generally only use a very slight sprung joint if it's a long glue up (over 4' or so). Once you get full length shavings, take a short pass in the middle, then a pass or two getting longer towards the ends. This creates a slight concave or convex curve on both boards that you use your clamps to overpower the board and pull them together. If you don't know if you need a spring edge/sprung joint or not, you probably don't need it. Further reading: https://paulsellers.com/2014/10/questions-answered-spring-edge-edge-jointing-boards/

That's better. Keep going until you get full width shavings from both pieces, from start to end.

Lay down some paper on your workbench (if you care) and put your clamps down. Bring your edges back up making sure you remember how to lay them back down once they're glued to complete your triangle again. NOTE: If they are really skewed, or if you're doing a complex glue up, or if you want extra assurance everything will line up properly - you can use dowels/biscuits/etc here to allow the pieces to line up on edge. Just make sure you've got enough depth and there's no debris or tear out and you can get a full flat glue up.

This is the glue I'm using, just in a fastcap glubot.

Apply a light layer of glue on both sides and spread it out across the edges. A strong glue joint is the one with the thinnest layer of glue, so don't go overboard. You can always add little dabs of glue as needed to get full coverage.

Put painters tape on your bar clamps. The glue will blend with the black color from your bar clamps and can stain the wood where the joint is.

Clamp (or line up your edges) and start applying clamping pressure. Apply small amounts of pressure at a time while alternating clamps until you get a good flat connection between both edges and glue is squeezing out. There's no reason to really crank down, just apply enough pressure to keep it nice and tight and flat is all it takes. Note: You can see the triangle I was talking about earlier in this picture.

Wait about 10-15 mins until the glue is a gummy consistency, then use a scraper or chisel to scrape the excess glue off the joint as needed. It's much easier to clean it up now than when it fully cures. If you're going to continue planing and sanding after the glue up, you can use a wet rag to wipe up the excess glue before it turns hard. Be careful in doing so not to spread out the glue or push wet glue into pores and possibly interfere with your finishing later in the project.

Now I have no excuses like "I'm waiting on the glue to dry" to get started on the actual piece... Note where the piece of blue tape is still there, that would have been a dark black stain without the tape.