Get rid of useless content assist choices
By default, Eclipse puts three things on the content-assist (CTRL-SPACE) menu: Java type proposals, JPA Proposals, and Template Proposals. The first time you hit CTRL-SPACE, you get the types, then the second time JPA and the third time templates.
Ugh! This sucks, especially because most of the time JPA and templates are empty.
You can turn this off easily: go to Window... Preferences then choose Java... Editor... Content Assist... Advanced. Remove JPA and templates from the cycling configuration (the bottom window).