One of the most important steps to becoming a minimalist is throwing stuff out. Follow these guidelines to help you out:
1. If you haven't touched/thought about it in 4-6 months, you don't need it
If it really mattered that much, it would have crossed your mind at least once.
2. If you have 2 of the same things (besides socks, underwear, the obvious), throw it out.
It's just taking up space
3. If it doesn't fit or is uncomfortable, throw it out (or donate it, of course)
Make more room for the things that you love!
4. Don't be too sentimental
Do you really need those love letters from your middle school crush?
5. Throwing out means you can buy new things!
But not too much, or else it completely defeats the purpose.
6. Know your boundaries
Obviously don't throw out a family heirloom or birth certificates.