This largely depends on what you are trying to do. So many of my sites are so different that I wouldn't get much of a time savings by setting up much of anything in the DB for re-use.
However, here are your options in general.
The NSM site genator looks promising and it's all open, but it seems to have been light on activity lately. The last commit appears to have been 5 months ago. Dead project?
If you do a search for "import" at http://devot-ee.com then you will see a lot of add-ons which you can use to import data in other formats. Because the control panel is the slowest cog in the process, I think creating data in X format using offline tools and then importing that data would save a bunch of time.
You could also just setup add basic items to a bootstrap base install of EE, but again, it's the control panel which slows me down. So, an importer would be faster.
Certain modules from developers such as Solspace provide auto installs to get examples for their add-ons working. This can be quite helpful at times, especially if you have never worked with the add-on before.
Of course, the items which jumps out to me is that you don't know Git. Fix that! By far you will get the most benefit by setting up one base install, copy that to your repo and then clone that repo for each new project.
Also, more and more, developers and clients are expecting to have the development backed up in a version control system. Using Git also gives you more options for fast deployments, and this can save you a lot of time and headaches as well.