I would say that almost all “serious” amateur webmasters use adsense (or something very similar). And of course, you want to bring in as much revenue as possible. Over the years I’ve made a fair amount thanks to Google, and have worked out what works and what doesn’t. (Tips after the jump)

• Blend your Adsense ads – don’t put bright red ads on a white, minimalistic page. Like many advertisers say, the best ads are those that people do not realise are ads
• Minimize other links - if your site is only of those small mini sites set up just for adsense (aka “Adsense sites”), don’t give the user too many options. If you list 20, 30 or more site links as well as your adsense ad you are going to get a lot less clicks on your ad than if you only have 1 or 2 links. This can hurt your search engine rankings a little, but it does help increase CTR
• Read Google’s own tips – they want you to make as much as you can, as it obviously makes them money as well. Their page about best ad placement on pages is very handy
• Track individual ad units – use the channel feature to track individual ad units. The more ad units you show, the more chance of low paying ads that are shown. So get rid of any that don’t get a decent amount of clicks (compared to other ads on the same page)
• People don’t think before clicking - this sort of follows on from my first point (blend it). People know that blue (and also underlined) text means links. Making the ads text blue can help (it depends on the target market – I found it didn’t make much difference for tech savvy users).
• Use the wide skyscrapers – these always seem to convert the best. And take a look at any large site that uses Adsense and you will see they use them.
• Use inline ads – these are ad units that are placed so they look like more of the content, than part of the layout. They have a higher (on average) CTR.
• About to make an Adsense site? - aim it at kids, or at least not geeks! It is true… Geeks hardly ever click ads.
• Try making your site hard to navigate – similar to another point above (minimise links). If your site is hard to navigate there is a higher chance people will click your ads (if they are clear). Of course, this is more for those spammy adsense sites rather than any quality site.
• Don’t ignore the search feature – put in the Google search box, and make a bit of extra money if people can’t find what they’re looking for on your site

Use tips at your own risk :)