How To Cache GPG Passphrase In Ubuntu

I got into Debian packaging and one of the most brutal part was to type in the GPG secret key’s password every time I sign a package. I wasted a lot of time typing my long password. I searched a lot to cache my password for some time after I type it once. All of them said to edit gpg-agent.conf, but none of them worked for my fresh installation of Xubuntu 16.