Looking for advice on filling a gap between wall and sink

[procon]

6. We're in the midst of a kitchen remodel too, likewise

we had old walls that were uneven and caused gaps where the base cabinet touched the wall. What we did was apply drywall mud to the entire wall before the installation of the cabinets to float out low spots and bring them flush with high spots to make the wall straighter. In really bad spots we applied multiple layers of mud, just be sure to let each application dry thoroughly. We then put in a subway tile backsplash tile and used additional mortar to build up the last uneven spots and make everything straight, and now you can't see any imperfections. I am very happy how it turned out!

We had also thought about other options like replacing the old drywall on one really wavy section with new drywall, or using thicker stucco to build out the low spots followed by a smoother plaster finish to make the surface flush, flat and even before applying a texture coat.

Good luck!