Digressing for a moment here:
- You don't need to insulate your conductor (e.g. paper clip); it is connected to ground only, which is 0v
- You certainly do not want to insulate it with cellophane tape since the tape is electrostatic charged
- You do, however, want to ground yourself and your tools (in this case, the conductor) prior to touching your phone by touching anything connected to earth ground (i.e. metal power strip, PC case) and either stay grounded or do not move or touch anything else prior to or during touching your phone. A grounding strap is ideal but isn't necessary.
If your SD card got nuked, it was a result of electrostatic discharge (it isn't an ESD card nyuk nyuk) rather than grounding it (since it is already grounded anyway).