Well, a month later I am finally finishing tips to keep the ribs up during the rest of Basic Workout Plus (BWO+)!
First I want to share a tip I found on the forums (remember how encouraging and helpful I said they are?) that helps you focus on lat engagement. This was posted by ayj on the forums:
So, what it is think squeezing an imaginary pencil between your shoulder blades without using your shoulders, while in the whole time your lower back is tight trying to help too (your tummy and upper abs will be tight too). Maintain this squeeze on the imaginey pencil the whole time during the work out, I am sure I will not be able to do 45 mins this… This will certainly burn back fat and tone and tighten the abs.
The trick is to not squeeze the shoulder blades together and be overinvasive that way!
Now, how about the rest of BWO+–how do the lats/ribs up figure in to the last 4 moves?
We’ll pick up where we left off–ready for The Box!
I had posted this before, but this clip from Fox Atlanta shows the Mitten Chop Box, which gives a new twist adding to muscle activation–and especially helping to get those ribs UP! When you’re doing the regular Box in BWO+, as you’re pushing in the hips with those thumbs, get those elbows back and lift the ribs/set lats. Just like PBS, as you go over to a flat back, really try to balance a beach ball on your back, pulling tummy up and into the spine. Tighten the buns and press the breastbone to the floor to help get ribs up and lats engaged. As you pulse there, use tummy muscles–not the back!–to do the pulse. NO momentum!
Then when you do the side tilts, again, push in with those thumbs to activate the arms and lift the ribs as you tilt. Think of breastbone to the ceiling now. We’re trying to elongate the rib to hip area–making room for the organs and helping cinch in the waist!
Oil Wells–yep! You can keep ribs up here, too! Again, as you go to a flat back, follow all the tips for PBS, only instead of pressing thumbs into hips to activate arms, now you are hooking the thumbs to pull while pressing the insides of the hands together to create the leverage isometrics. Then as you “reach through” for Oil Wells do not hunch up your shoulders or release your lats! Continue to keep shoulders back (by using the lats) while reaching through.
After you roll up and have your hands above, recheck your form–bend knees, tuck/curl core, lift ribs, push knees out–then pulse your hands above.
T-Tapp Twist—ahhhh! The move you love to hate! We love how it blasts hip pads and cinches in the waist, but we just hate to do it! It is really tough, especially in the beginning!
Try this on in a chair, first. That will help you get the lower body isolated without having to think so much about it! Toes forward, knees over ankles and knees also straight out from hips. Press the feet lightly into the floor (keeping KLT!), and sit tall. You can still slightly tuck the tail under and curl your core. Now lift ribs!
Press your hands together–lower hand pressing up, upper hand pressing down–at about your chin, elbows out to the sides. Slowly lower your hands, and somewhere between the collarbone and the chest, you will feel your lats kick in. Find that point for you. Now, as you press those hands against each other, lift ribs a bit more. Try to keep that activation as you execute the T-Tapp Twist move–left for two counts, then right, thinking back elbow stays up shoulder level at all times (to protect the back) and ribs up, ribs up, ribs UP!
Pause here, then tilt over to your right side, reach for the back leg of the chair, but don’t focus on how far down you can go. Keep those hips planted in the chair, keep your tummy tight, push your left knee out a bit to help stabilize your hips, and only go as far as you can without losing that tummy activation.
Press hands together a bit more to help initiate the roll-up from the tummy. As you get to count 3 or 4 to get all the way to the top, press and lift ribs. When you are doing this standing, this is also a good point to square the hips again to the front (they tend to drift a little!).
Pressing the hands together helps keep the arms, tummy and lats activated!
Now try it going to the other side, then try it without the chair! 
Pull the Weeds–just like PBS and other flat back moves, press that breastbone to the ceiling and pretend a string is going along your body helping to pull the vertabra apart. As you pull the elbows forward (like a scarecrow), don’t hunch! Tighten those lats!
Finally–Hoedowns! Oh, here is a GREAT one to keep those ribs lifted!
Get into position–toes forward, bend knees, curl core, ribs up and push knees out. Shift over to one foot, get the other ready to lift touch. Put hands in front, elbows bent, palms up and slowly open out to the sides. Really tighten those mitten hands–no mushy mittens! That will help tighten the upper back–and you got it! The lats!
Now as you actually lift and touch the leg, keep thinking to lift the ribs–and keep the mitten hands tight! It’s easy to get all focused on what the lower body is doing and collapse the ribs and core!
Keep that form through the second side on the second set! Don’t collapse!
You DID it! 
So keep those ribs up and–Happy Tappin’!
(Just a note about the Green Smoothie Challenge–it will be available until May 16, and it is now $59.95. My understanding is it will go up in price each week, so if you’re still thinking about it, you might want to grab it soon! )