Waterslide decals

Best decal application tutorial ever:

https://youtu.be/L_rdwH1EGus

Artillery

I'm not new to models but I've never been able to get the hang of water slide decals and recently I bought some mr.hobby decal softener and setter but I don't know how to use them properl or effectively I would love and greatly appreciate some help advice and tips thank you  

What kind of problems have you had?

As far as the solutions go, they help the decal snuggle down on the surface.  The difference between the two "types" is strength.  Essentially, they soften or dissolve the color film, and as they dry, deposit the color onto the surface.

I use (in order of "heat") MicroSet, MicroSol, and Walther's SolvaSet.

Back in the day, some modelers just used white vinegar; acetic acid can work just as well as commercial solutions.

I use warm water to soak the decals.  I keep it in a small bowl that fits on a mug warmer.  If there are instructions printed on the sheet (eg, on the back) I will note them.  But generally, I let the decals soak for about 30 seconds, then use a tweezers to remove it from the water.  Some decals take long.  I use the tweezers to place the decal over the area where it will go-I try to hold the piece so that surface is horizontal-and I use a paintbrush to slide it off the paper and adjust it.

I use a piece of paper towel to wick away the excess water, then hit it with whatever solution I'm going to use.

If the decal is thick, and won't settle easily-on compound curves, say-then I'll use a fine sewing needle to poke holes in the film over those spots, and apply the setting solution.  Sometimes I've even used the tip of a Nr 11 knife blade.

Some decals will wrinkle under the solution, and it can make you panic, but I learned that when that happens, just to be patient and wait.  As the solution dries, the decal will settle down.  If there are still some wrinkles at that point, I'll apply a little more setting solution.  Again, I've got old paintbrushes that I use for this kind of work.

Some things can go wrong, and it's not your fault, not something you're doing wrong.  When I built ICM's 1/48 P-51B, I found several of the decals prone to curling. Not all of the decals on the sheet, just some.  Again, a paintbrush helps if you have to straighten out a decal that's folded or curled back on itself.

I don't know if that helps, but that is pretty much my process for applying waterslide decals.

Artillery

mr.hobby decal softener and setter

If you mean Mr Mark Setter (wit the blue label and cap), as far as I'm aware, it's different to every other decal setting medium. The difference is that it contains an adhesive component and actually helps to glue the decals down on the surface. It's useful when using old decals or decals which have been soaked too long, where the glue no longer sticks. 

In my opinion setting solutions are very useful.  Solvents can improve problem decals but there are risks to using it. I do not use it regularly- only if I really need it.

Heat helps sometimes, but be very careful. If a low power low temp heater like a stamping heater, okay, but with a regular full size heat gun stay way back and do it in quick passes.

Warm water helps too.

I use Future as a setting solution sometimes, too.  I generally use it as a gloss coat before decaling, but I sometimes put a little fresh liquid where the decal will go.  I've also used it to repair decals that cracked or flaked.  I put a little bit of the liquid down and then put the pieces back.  When that dries, I use a little more to seal it again, and then apply a matte coat again as necessary.

It's only happened once or twice, and I haven't noticed any particular brand of decal that is prone to this.  But it worked as a "meatball surgery" solution to the problem.