A few months ago when I needed to go to my local store I also bought a crackle paste and decided to give it a try. The paste is from KREUL‘s brand Goya.
I have to say I underestimated the skill required to get decent results. On one hand the crackles depend on the thickness of the paste, and on the other hand it seems it depends on how much you spread it in each direction. Looking back I would strongly recommend you add black pigment to the paste before applying it. As a second advise I would say, let it completely dry and set before painting it. I painted it directly after drying. This was definite to early. On the next day several additional cracks have formed, showing the annoying white from the paste. Therefore I needed to retouch everything with paint. Moreover – you may notice it on the photo – after several days there are a lot of new tiny cracks where the white paste shines through.