Developing creative in a vacuum is never easy, but here are some tips on making the process friction-free.

In a perfect world, designers would have a finalized media plan and complete ad specs just as they started to design concepts for the next ad campaign. But we don't live in a perfect world, and many designers can't even remember the last time everything went according to plan and they received all the relevant details in time to customize ads for a given media environment.

More than likely, their last campaign was designed in a vacuum, with little direction given as to where ads would run.

Designing in a vacuum is always a less than ideal situation, but the following are some tips that may help keep the process friction-free. If you're not designing for specific environments because the media team doesn't have the media plan nailed down yet, look at the bright side: you have the opportunity to gain more control over what ends up running.

While that doesn't mean you can create whatever ad size or format you want, you have a lot more influence over sizes and formats than you might if the media plan were fully baked.

Stay Within Expectations: Obviously, the client is going to have a heart attack if, at the end of the creative approval process, they have a bunch of 30-second pre-roll videos and the media plan ends up calling for IAB standard banners. Even if a plan isn't finalized, the media folks should be able to give you an idea of what you should be producing. When we know we're buying standard ad units, we generally tell our creative teams to produce concepts that won't incur additional fees to run, so...

• Steer clear of third-party rich media vendors
• The same goes for ad formats that cost extra from a placement perspective, such as pre-roll or standalone video (in-banner video is okay), page takeovers, roadblocks and peelbacks
• Any rich media should stay in the banner space and be servable through the agency's ad server (think DoubleClick's Motif or Atlas Rich Media)

Always check with your friendly neighborhood media guy if you're concerned that something you want to produce might cost extra to run.

Push Toward Effective Sizes: While you might not be able to produce specific ads for specific environments, you can still draw some conclusions about the variety of ad sizes available on a typical ad-supported site.

One of the variables we've been examining closely is the typical proximity of different ad formats to content. It's a working theory here at the office that the closer an ad placement is to the actual content of a web page, the more effective the ad placement is at driving both response and brand impact.

We see this notion play out when we look at rectangle ads, such as the 300x250 and 336x280. Generally, these ad sizes tend to enjoy close proximity to content, since text is often wrapped around them.

Even when pages don't wrap content around rectangle ads, they tend to feature them in places where they're tough to ignore.

Leaderboards and buttons are often in the same spot on many pages, thus making it easy for people to tune them out. You'll see a lot more variety in how rectangles are placed on a page, and this helps them get noticed.

Speaking of the leaderboard, the single most popular ad format on the web has been experiencing declining performance for quite some time now. Perhaps it is because the ad format is typically separated from content -- running at the top and bottom of pages -- and it is often separated from content by vast expanses.

Many sites run the leaderboard format at the very top of the page, above all the navigational elements.

This puts the leaderboard at a disadvantage. Not only do people tune it out because they see it at the top of every web page, but they also find it easy to ignore because of its lack of proximity to the page elements they're actually looking at.

While it's true these are generalizations, as a designer, you can surf through some of the sites under consideration on the media plan (or sites that make sense for the target audience) to see if there are any commonalities in how different sites use the same ad size.

Don't Forget Rich Media Standards: If you are producing Flash to be served through your agency's server, don't forget about the standard specs for tracking, and the various standard methods for streaming, click commands, expansion and other ad functions.

In my experience, there have been numerous times over the past few years when creative and media teams working in parallel failed to communicate effectively and the ads didn't work properly in the ad server test environment. Or the publisher rejects ads that don't use the proper code specs. It happens.

Don't forget those click commands and standard methods. It's no fun to be re-coding Flash ads on a Saturday.

Tom Hespos is the president of Underscore Marketing and blogs at Hespos.com. Read full bio.