  We show Strichartz estimates for quasi-periodic functions with decaying
Fourier coefficients via $\ell^2$-decoupling. When we additionally average in
time, further improvements can be obtained. Next, we apply multilinear
refinements to show low regularity local well-posedness for nonlinear
Schr\"odinger equations. For the cubic nonlinear Schr\"odinger equation the
approach yields the sharp local well-posedness result.
