A good trick is to learn to draw in real life. Usually the two go hand in hand - I don't think I know of one person who's a very good pixel artist but can't draw on paper (there probably are some, but I've certainly not heard about it).
Look at the work of others. You can pick up some good tips and tricks that way.
Practice.
Don't expect to make stuff like Eternal Daughter in just a few days, and don't compare your creations to the work of artists who've been pixel-wielding for years.
A good trick if you're a good artist on paper but rubbish with a mouse is as follows (I used this in a few games I never finished, but the results were quite good):
You will need a layer-enabled program, like Paint Shop Pro 6 or above (I use version 7.2).
Draw on paper your sprite. Make sure you've gone over the lines in a thin black pen. Scan it. Shrink it to the size you want it in pixels.
Now either: create a new layer and trace over it pixel-by-pixel, OR, convert it to monochrome (2 colours), then back up to 16 million. That'll convert the lines into pixels. Then just clean up deleting any stray pixels and making the lines all 1 pixel wide.
Fill the areas with colour. Then select each area and start shading it using darker and lighter colours.
Once all your shading is done, use the colour-replace brush and start going over your black outlines, replacing them with a darker/lighter version of the surrounding colour. So a bush in the light of a sunset will have a very dark green on the darker side, and a kind of orangy colour on the lighter border. Then blend them in between.
I did that a few times, especially for big pixel-art-scenes were a smooth drawing just wouldn't fit with the rest of the game.
"A good trick is to learn to draw in real life. Usually the two go hand in hand - I don't think I know of one person who's a very good pixel artist but can't draw on paper (there probably are some, but I've certainly not heard about it)."
I suffer from this, I'm totally hopeless at drawing by hand, but oddly enough my spriting skills are much better. Heres a screenie of my current project...
im fairly average at drawing paper and pixel but i never say i can't draw whatever. I just give it a go.
See my avatar? i just did it by looking at anime faces for a bit.