These tips are courtesy of Design Democracy's Arnold Dela Cruz:
As the creator of a network about and for designers, one of the first things on my mind was how I was going to customize the look and feel of my network to establish its identity and character. A number of Ning Creators, not content with the default themes Ning offers, are adept at developing CSS (Cascading Style Sheets) to achieve just that. But I would guess there's a larger number of Network Creators who either don't have the knowledge and expertise to do this or may have dabbled with it but with less than desirable results. Below are five basic tips for styling your network. It's neither a tutorial nor a comprehensive set of design principles — more of a primer if you will.
1. Have a plan.
Before you build a house, you need a blueprint. The same goes for styling a Ning Network. I use the term, "styling," as opposed to "designing" since the bulk of layout and graphic design was done by our friends at Ning. The decision to customize your Ning is really not that different than deciding to put a different set of clothes on. The basic DNA remains intact and only the outward appearance changes. This is done through CSS.If you don't know CSS, there are tons of resources on the Web. I recommend visiting the w3schools.com tutorial on CSS. Using your favorite graphics software (I use Adobe Fireworks CS4), create a few mockups (or prototypes) and narrow down to best two or three and then finally to one. Use tools used for web development like Firefox and browser add-ons for tweaking CSS. One of the first few add-ons I strongly recommend installing are: Mozilla Firefox Add-on Collector, Pro Developer, Web Developer's (https://addons.mozilla.org/en-US/firefox/collection/webdeveloper), Firebug, Web Developer Toolbar, ColorZilla andTypeGauge.Since each Creator is permitted to create up to 10 Ning Network with a single email address, you can use one to create your own private laboratory for developing and testing your CSS before applying it to your network. You can easily keep prying eyes out by setting the appropriate privacy levels.Another good piece of advice as you get started is to regularly keep backups and versions of style sheets and scripts as you go along. This is useful if you mess up or want revert to a previously used theme. It’s also helpful to get in the habit of commenting within your style sheets to help you remember what you did.
2. Focus on content and usability
I have this family relative who I often dread having conversations with. Not because they're dull or crass but because they wear nauseating perfume you can smell from the barbecue pit at the family reunion.
Show constraintDon't overdo the design just because you can. The temptation to "bling" your Ning may goad you into splattering your network with garish animated GIFs, particularly of the sparkly kind. IMHO those are distractions not attractions.
Keep your audience in mindThe spirit of Ning is not about the individual but about fostering community. Just because you like the gothic look and feel of a certain vampire film doesn't mean your network of puppy lovers will.
Note how things work togetherUse contrast and rhythm through good typography (see The Elements of Typographic Style Applied to the Web (http://webtypography.net) and Smashing Magazine's "50 Useful Design Tools for Beautiful Web Typography" (http://www.smashingmagazine.com/2009/01/27/css-typographic-tools-and-techniques/) , colors (http://vandelaydesign.com/blog/design-process/color-schemes/) and negative (or white) space (http://www.tutorial9.net/resources/enhancing-your-art-with-negative-space/>.
3. Style communicates more than just looks
Style or the lack of it subconsciously tells a user what your network is about. It sets the tone, voice and character of the community. Whenever possible and feasible, use a professionally designed logo instead of the default web fonts in your header. Designed and used well, a good logo gives your network a distinct identity.
4. Test and test often
Don't rush through your design. Take the time to make sure your code is clean, there are no typos and that you've covered everything you need to, before going live with it. Invite someone (or a few people) whom you trust to give you honest, constructive criticism to enter your lab (see point one about setting up a test environment) and be willing to take it into consideration.While Ning's developers have done an excellent job of creating a rock solid framework that works across most major browsers in use, your CSS customization could jack things up. Test in multiple browsers before releasing on your network.
5. Be open to feedback.
Wait a while between major revisions to your design, and listen to your members when they offer feedback and suggestions regarding the network's design. But remember: you can't please everybody so don't try to.