Freelance digital artist Travis Davids shared a free set of his personal favorite alphas that he uses in his projects. Get creative with them by layering different alphas on top of each other. The pack would be classified as industrial so it is said to be useful for any quick hard-surface detailing.
To fix jagged edges that are sometimes visible by applying the alphas, smoothing it a little bit by sacrificing some of sharpness applied by the alpha should fix the problem. Alternatively you could sub-divide your model further.
You can also use an alpha to create quick geometry using Shadowbox.
For optimal results, make sure your poly count is fairly high in order to get crisp details.