Yes for *waterslide decals* you can (and I recommend you do) use things like MicroScale Set/Sol to prepare the surface and soften the decal, that's why you get a "painted-on" look.
As far as stickers, my suggestion is: Don't use them... The reason being simple that they really make your model look non-realistic and toy-ish. I'd rather mask and paint than using stickers unless it's a place that's hard to do masking.
That's my two cents. Hopefully it helps. :D