Paint Finishing Effects

Crackle Finish

Apply a base coat of paint to the project surface, and let it dry. The base coat will show through the crackled top coat, so choose paint colours that contrast nicely.
Brush a coat of "clear crackle-finish medium" onto the piece. The crackle glaze usually takes 30 minutes to an hour to dry.
Apply your chosen top coat paint, loading the brush with enough paint so that each section can be painted with one motion. The crackling begins immediately on the first layer of paint it comes in contact with. Avoid over-brushing, which will just cover the crackle effect.

Dark Wax Effect.

The purpose of using dark wax on painted furniture is to give the effect of a patina, which will make your item look naturally aged and antique.
There are several ways of creating this effect with wax, but here is the one we feel gives the best results:
Make sure your painted surface is completely dry.
Use an old paint brush to apply the dark wax, making sure you get right into all the corners, details and carvings. Do not apply a thick coat as this will make the next step much harder for you.
This doesn't have to be a particularly neat process, as this is just the starting point.
Leave the wax to set, usually about an hour.
Now apply some clear wax to a clean cloth/rag, and start applying it to the item over the dark wax. The purpose of this is to remove most of the dark wax, just leaving some in the grain of the paint and the detailing and carvings. How much you remove is up to you. Keep rotating the cloth in this process, applying more clear wax.
Once your happy with the effect, allow the wax to set.
With a soft woollen or cotton rag, gently buff the wax to a shine. The buffing process is important as it gives the item a smooth surface and allows any spills or drips to just run off it, and makes it a little more durable.

The "distressing" process does seem very counter productive, as effectively, you are undoing all your hard work. However, finished results can give an authentic aged look that can highlight the shape, carving and mouldings on your furniture item.
Before starting, ensure you have given your item enough coats of paint all over, and make sure it is dry before beginning the fist step.
This is an artistic finish, so it really depends on the style you are going for, but i would recommend using 100 grit sand paper. This is rough enough to cut through the paint and a little of the top surface of the furniture item to reveal bare wood.
Place the sand paper into a sanding block, or fold and use directly with your hands. 

Now, start to analyse the item, and think, if it had been around for 100 years, what parts of it would get the most wear and tear or usage. For example, the base will tend to get scuffed by feet, corners and edges have the smallest surface area and are more prone to wear and tear. Areas around the handles will always get touched. These are all the areas that you need to focus your distressing technique.
Its always a good idea to do this step with good ventilation, a dust mask, and if indoors, a hoover to hand. Start by gently running the sandpaper against the paint in the areas you have picked to distress. I usually try to keep this motion all in one direction as it gives a smoother distressed look, but like i said, this is an artistic finish and you are the artist!
Do this in all the areas, just to highlight how much you are looking to do. This is a good opportunity to adjust how much you would like to distress. 
Once happy with the areas you want to apply this effect, begin sanding a little harder. Sanding harder in areas of most "potential use". Again, in this step, i would expose some of the wood under the paint in the most used areas.
Remove all dust. If  you have a small brush accessory for your hoover, this works great! If not, with a soft bristle brush, dust of all the removed paint and dust. Now with a tack rag or a very slightly damp cloth, wipe the item all over, removing any fine remaining particles.

Seal the item. As you have begun the "distressing" effect, without sealing the paint, more paint can flake off as it is easier to distress naturally with your own usage of the item. So to keep the item looking exactly how you want it, either seal with a wax or varnish at this point to finish!