Pine can be given a "weathered" look by using a coarse wire brush (powered). It removes the softer wood fibers letting the features of the rings stand proud. A gray stain completes the look.
A crackle finish can be had by applying a coat of varnish and after a two to three hour wait, applying a 1:1 mix of shellac and denatured alcohol. Applied at two hours after varnishing, large cracks appear- smaller ones are produced after longer varnish drying time.
Always test on scrap before committing to any finishing procedure.
"Safety... Always" Hank Metz Producer, "Biscuit Joinery Techniques" video