The worst part of the whole renovation 
I really hate the strips, from what I've "read" in theory, you're supposed to use a special joint filler that's a bit wetter. The first round is only joint filler and strip, no layer on the strip, and when it's dry, a new layer without touching the strip.
Personally, I find it difficult to make it work and do as the previous person in the thread. I use wetroom glue and strips on that, and when it's dry, I apply filler
I really hate the strips, from what I've "read" in theory, you're supposed to use a special joint filler that's a bit wetter. The first round is only joint filler and strip, no layer on the strip, and when it's dry, a new layer without touching the strip.
Personally, I find it difficult to make it work and do as the previous person in the thread. I use wetroom glue and strips on that, and when it's dry, I apply filler
Use the same method as above. Alfa DIY-ers claim that it is easy to attach the strip with joint compound, but I have never managed to do it.
I forgot to mention that I use paper strip when wet gluing the strip.
Brush on the wet room adhesive in the board joints and then attach the paper tape. I usually press down the tape with a putty knife by pulling it over the tape. Do not use fiber tape, it is not as durable.
You don't need any glue with tape. Stick the tape on and apply a few layers of filler, and it will be fine. I know many don't like it (especially here on the forum) but it's well-proven and works, even though it's probably a bit worse than a 100% correctly filled paper strip.
Wet room adhesive works fine! Apply thick and even with adhesive, using a small roller or brush, then when the strip is in place, apply a layer of adhesive on top of the strip immediately. Do not press too hard on the strip, as there is a risk of pressing away the adhesive underneath the strip. The same method applies to drywall compound!
Paper tape has been preferred for a few years now; before that, fiberglass was the go-to, so use what you're comfortable with.
But simply do it like this:
Apply joint compound and install the tape, smoothing it loosely with the trowel. Let it dry, then apply more joint compound.
If it doesn't work, you can try one of these methods:
Install the tape, apply joint compound.
Apply joint compound, dry, then tape, and apply more joint compound.
You always need to apply joint compound at least twice.
Sand between each application but not so hard that you sand off the tape’s fibers.
But simply do it like this:
Apply joint compound and install the tape, smoothing it loosely with the trowel. Let it dry, then apply more joint compound.
If it doesn't work, you can try one of these methods:
Install the tape, apply joint compound.
Apply joint compound, dry, then tape, and apply more joint compound.
You always need to apply joint compound at least twice.
Sand between each application but not so hard that you sand off the tape’s fibers.