Okay, let's face it, pictures are essential to every story that's posted here. After all, a picture is worth a thousand words (or so they say).
There are plenty of threads out there that explain techniques to take pictures, so this will be brief and the example pics will be minimal.
A lot of people choose to take pics first and write afterwards, and a lot of people choose to write the story first and take pics to complement it. Either way can work for you! Just choose what you feel most comfortable doing.
Here's a few pointers to work with:
Game Issues and Shot Angle:
The biggest problem I see is people who take bottom-up shots from inside the house, and you can see the sky over the walls. Someone did a very lovely Ceiling Tile mod that can be found (correct me if I'm wrong) on MTS2 that enables you to get the perfect shot without catching vast expanses of sky. Otherwise, just get creative with your shots!
Also, I always find it a little strange to see shots done with Walls Down. Really, you shouldn't be able to see into the bathroom and the kitchen if you're taking a pic from in the living room--and vice versa! If at all possible, try to get the shot from inside the room with the walls up.
If you're taking pics from outside, you should also make sure that the roof is visible as well as all of the floors (when you're using a multi-level house).
If all of your pics are of one type of depth, your story won't have the same impact as it would if you varied shot depth.
Shows one small part of the subject of your scene. Head-and-shoulders shot.
Shows about half of the subject of your scene. Waist-up shot.
Shows most or all of your subject. Full-body shot.
Extreme Close-up: If you took a picture of only your Sim's eye, it would be an extreme close up.
Extreme Long Shot:
Assuiming that the little girl is the subject of this photograph, this is an extreme long shot. The surroundings take up more of the photo space than the subject does, usually.
An extreme close up would be effective to show a single tear running down someone's face.
A close up would be effective to show someone's strong reaction to a conversation.
A middle shot would be effective to show a hand gesture that someone is making.
A long shot would be effective to show the stove burning and someone standing across the kitchen freaking out.
An extreme long shot would be effective to show someone wandering between tall buildings in the city.
A good mix of these depths used appropriately makes your story visually appealing!
I've also found that the most interesting stories have an average ratio of less than three paragraphs per each picture. Keep in mind that if your pictures are expressive enough, you can tell an entire story without a single word! In fact, even if you intend to include text, your pictures ALONE should still allow the reader to make a close guess as to what's happening. (Try showing someone the pictures without text, and ask them what they think is happening--the closer their guess, the better job you've done!)
This is really up to you to decide what you want to do in this department, though. There is no "right" and "wrong" when it comes to the amount of pictures you choose to post.