Sign of Feynman rules with derivative couplings

Feynman rules for derivative couplings always make me confused. For example, the derivative in $gV^\mu\phi^+\partial_\mu\phi^-$ will give you $\pm ip_{-\mu}$, where $\pm$ depends on whether the particle is outgoing or incoming.

I found "$-ip_{-\mu}$ for incoming" in Peskin & Schroeder's QFT book, BUT I also found "$-ip_{-\mu}$ for outgoing" in some other literature. So I'm wondering if the latter one is wrong. Or are they just in different conventions so that we can choose either of them?

The sign convention used here depends on the metric signature convention and on the convention used in defining the coupling. In Penskin and Schroeder, for example, the QED coupling $e$ is defined to be negative, so an extra minus sign may be found if comparison are made to other texts.