One of the things that I don’t like about the default Eclipse settings for Java development is that in the package explorer all Java files appear in the same manner(with the same icon). There is no visual distinction between abstract and concrete classes, enums, interfaces… Luckily for us Eclipse supports such a distinction and all you have to do is enable it.
Go to Window -> Preferences -> General -> Appearance -> Label Decorations and mark the check box saying Java Type Indicator. I’ve tested this on Eclipse 3.5 only, but I guess it is included in previous releases as well.
Eclipse, though not as feature rich as IntelliJ IDEA, offers a lot of features that one has to find for himself.