2) Budget a LOT of time. I'm sure experienced swatchers can do this more quickly, but it took me roughly 30 - 45 minutes per colour to do the full swatching/clean up/picture editing/posting on the blog. For the 11 colours I did, I spent about 4 hours on polish, and 2 - 3 hours on photo editing and posting. That's a LOT of work!
3) Sunlight is mandatory for great colour! Unless you have a professional photo studio, which I do not. I use a simple point and shoot camera, some white paper to provide a clean background, and the sun.
4) Keep an eye on the weather forecast! Living in the north, I'm at a serious disadvantage in winter when it comes to the window I have for swatching. At this time of year, I have a few hours of good strong sunlight that will let me take nice pictures, so I took advantage of every minute. Once summer rolls around, I'm sure the advantage will skew in my favour - I look forward to it!
5) Keep a glass of water nearby. Between the polish fumes and acetone fumes, your throat will get scratchy and dry. This leads directly to...
6) Work in a well-ventilated area to reduce exposure to noxious fumes. Acetone is NOT a fun thing to breathe in!
7) Do the colours you're working with really need a base coat? If it doesn't stain, then don't waste your time. And don't assume that dark colours will stain while light colours won't - ManGlaze's Fuck off and Dye is a hot pink that will stain your nailbeds as soon as you put it on, while the Deborah Lippmann Edge of Glory black creme I had on today didn't stain at all with no base coat through several applications. Test and be sure!
8)  Be expedient. I've yet to take a single picture that shows my thumb or my right hand, so now I just polish the four fingers on my left hand. This saves a lot of time and clean up!
9) Rushing your polish job will just end in misery later when you try and fix your mistakes in Photoshop. 
10) On the topic of Photoshop, learn what's an easy post-processing fix, and what's just an invitation to torture. Ding your creme polish a bit? Not a big deal - that can be quickly and easily fixed in Photoshop. Got polish along your cuticle? You're gonna pull your hair out trying to fix it.
11) A small cosmetic brush and a bottle of pure acetone are your best friends for cleaning up your manicure. Take your time and gently brush away any mistakes along your cuticle, edges, and sides of your fingers. The pure acetone will just eat away the polish, so be careful! 
12) Every second you spend cleaning up your nails before you take a picture means minutes saved afterwards.
13) Even if you don't see the mess on your nails, your camera will. A high resolution macro shot in sunlight is extremely unforgiving - every speck of stray polish, every bit of dry skin, every stray piece of pet fur will show up.
14) Just because you can't see it, doesn't mean it's not there. Even if you can't see a mess on your cuticles, run the brush over them anyway because the camera will.
15) Think you're in the safe from camera mistakes with your base and top coat because they're clear? Think again. The macro setting and the sun will reveal any clear polish on your cuticles or fingers, making them look uneven and messy. Make sure to swipe the brush along your cuticles after your topcoat too!
16) When you finish cleaning up your cuticles with the brush, take a cotton pad and wipe down your fingertip and around your nail. This will clean up any polish that dripped with the acetone down your skin and collected in any lines on your fingers. Trust me, it's there. You'll be amazed what comes off on that cotton pad!
17) After all that acetone, your nails and fingers are going to be super dry. Give them a good slather of cuticle oil afterwards to help smooth things over.
18) After your nails are nicely cleaned up, take your pictures against a clean white background. Plain old printer paper will work fine for this.
19) Take a LOT of pictures from a ton of angles! You never know what you're going to capture by moving the camera a bit. You can sort out the good from the bad when you're in Photoshop
That's it for now! I'm sure I'll have more to share as I continue learning how to swatch and photograph my manicures :)