Asphalt pavement is susceptible to cracking caused from forces below (usually tree roots) and impact above. Any small crack or hole in your asphalt should be repaired as soon as possible. The longer you wait to patch these holes, the larger they will become and the more difficult it will be to patch them. This article explains how to use cold mix asphalt patch for small jobs.
Using the Best Product
Cold mix asphalt is definitely the best product for small repairs. Hot mixture asphalt is used when large slabs are poured. In fact, the asphalt slab that you are patching was probably poured using a hot mixture. But, you should still use cold formulas for small repairs. First of all, the logistics of pouring hot asphalt are a real headache if you don't have professional asphalt equipment. The asphalt needs to be heated to a consistently warm temp while it being poured. If you don't have the tools, it will be nearly impossible.
Regardless, cold formula patch actually works better for small fills. When you are just patching a thin crack or small hole, you need something that will adhere to the existing asphalt, no matter how old it is. Cold formula patch is stickier so it will form a stronger bond with the old asphalt.
You also have the choice of buying premixed patch or the mixture itself. Buying the mixture is a better value because you get more. However, it adds an extra step to the project, so many just prefer using the premixed products.
Applying the Patch
The patch application is actually quite simple when you are just filling small cracks. First, you want the crack to be as clean as possible. Any dirt or weeds growing out of the crack should be removed. The job only becomes difficult if the crack goes all the way through the asphalt slab to the dirt underneath. When this happens you actually might need to fill the crack in with dirt to level it out.
When it comes time to applying the patch, you can basically spread it on with a large putty knife or squeegee broom. You might also need a flat wooden board (or you can buy a tamper) to flatten the patch and make it smooth. You can use the putty knife to taper the edges and ensure that there won't be any ridges when everything dries.
Contact a paving contractor for more help.