1. Check the tube side of your rim for any sharp protrusions and file/sand them if necessary,

2. make sure the spoke ends are in good condition and not poking the tube,

3. make sure the rim tape is of good quality and installed properly,

4. and make sure to reinstall the tube correctly or else it can pinch between the tire bead and rim, and thus tear in such a fashion so as to appear as a long, deliberate cut.

As for #4, it won't necessarily pop right away...