I wrote a sort of tutorial but it was a few years ago and I never really finished it. I need to sit down and write a new one because looking back there is some advice that isn't so great and a lot of extraneous detail. Also I'm a lot less a dick than I used to be.
That being said, in my experience the best application for pixel art is Graphicsgale. I'm not trying to put some better-than-thou spin on it - but after 10 some odd years of casual practice, I've yet to find a utility that is more user friendly and facilitates faster production. (You'd be surprised at the subtle ways that poor application design can slow you down. Those 1-2 second delays get to add up after an hour or two of work and can break up your workflow.)
But you really should try it for yourself. There's a bit of a learning curve, but it's not steep. https://graphicsgale.com/us/
There's no particularly 'easy' way to make pixel art look good - like any skill there's a lot of practice, study and self-loathing involved.
I'd recommend reading over the following links to get an idea of how to avoid some common issues that are unique to the medium, and some general theory on how to make stuff look nice with minimal effort .http://pixeljoint.com/forum/forum_posts.asp?TID=11299http://www.pixel.schlet.net/
(Pay particular attention to the discussion of clusters.)
Beyond that, everything I've done is Creative Commons, w/ attribution, so feel free to use and edit to your heart's content.
I need to set up a gallery somewhere but I'm honestly just too damn lazy.
You should be able to find everything I've done in here, in some fashion: https://www.dropbox.com/sh/38bt1mjiwbz4 ... Kgo3a?dl=0