I like mine really smooth, so I make the whole thing in a food processor.
You can use the "pulse" feature if you still want a little chunkiness, but if you want it really smooth, just process the heck out of it.
If you don't have a food processor, a blender may work too.
If you have neither of those, you could try a very fine potato masher
but that would be a lot of work.
For extra fanciness, I also like to top my serving bowl with a little pool of chilli oil to allow my guests to add spiciness if they wish.
cooking.stackexchange.com/users/6938/jkraybill
In my experience the two key factors to getting really smooth hummus are: Be sure that your chickpeas are cooked thoroughly.
This is not the time to leave them al dente, you want them to be completely tender.
Emulsify your hummus.
Puree your chickpeas, seasonings, and a bit of the cooking water until it is thick, but smooth.
Once you've got this as smooth as you can get it, slowly drizzle in your oil based ingredients (tahini & olive oil).
This seems to be the most important factor, as I've made incredibly smooth hummus without removing the chickpea skins.
cooking.stackexchange.com/users/16863/SourDoh
This might be helpful , they use baking soda to soften the chickpeas before and during cooking.
cooking.stackexchange.com/users/None/
One trick I've always used to "smoothen" things in the kitchen is to use a mesh strainer and a plastic bench scraper.
What you do is "push" the hummus through the fine mesh of the strainer after it's been run through the food processor.
This will give a very smooth texture and remove any large chunks that the processor missed.
cooking.stackexchange.com/users/19638/Dryden Long
In order to make really smooth hummus, you have to find a way to deal with the skins of the chickpeas.
One way might be a more powerful food-processor or blender, or simply more time pureeing, to get smaller chunks.
The better way would be to get rid of the skins altogether.
This is what a food mill is designed to do.
It purees the soft parts of food while holding back tough parts like skins.
Or you could peel the chickpeas.
One trick I heard uses two kitchen towels and a rolling pin: http://eatsblog.dallasnews.com/2012/05/paula-wolfert-smooth-talks-hum.html/
cooking.stackexchange.com/users/18644/Waquo
Cooking the chickpeas in a crockpot will yield a well cooked product that will puree into smooth hummus
cooking.stackexchange.com/users/19813/Xiana
I found many Chumus recipes online. The general gist is to cook the chickpeas for a few hours (or let them sit in water for a day, then cook them), grind them, add water/oil/Tehina/lemon juice, and salt/pepper.  The result comes out more or less chunky (not that there are pieces, but it feels thick). I've seen "professionally made" Chummus (like Sabra) come out rich and smooth.  How do they do it?
How to make smooth Chumus?
cooking.stackexchange.com
<beans>
cooking.stackexchange.com/questions/36113
cooking.stackexchange.com/users/19741/chummus
For an extra smooth result, remove the skins, use baking soda to soften the chickpeas before and during cooking, and cook the chickpeas in a crockpot. Pulsing the mixture with a food processor or blender will help to make it very smooth. Smooth hummus needs the chickpeas to be well-cooked. This can be done by adding baking soda to the water or cooking in a crockpot. A blender or food processor is considered another essential for making smooth hummus. A final factor is finding a way to deal with the chickpea skins. 
A food processor or blender is required to make really smooth hummus. Cooking the chickpes with baking soda or cooking them in a crockpot to make sure they are really soft is another tip. To make really smooth hummus, you have to find a way to deal with the chickpea skin.