It depends on your journal. Many still require that figures are supplied as self contained (no psfrag of overlaid LaTeX) EPS files. On first glance this would appear to rule out TikZ, but in fact you can still use TikZ, and employing the external library with the appropriate extra bits for EPS (see Export eps figures from TikZ) will naturally spit out EPS for you. When it comes to submission time, you can comment out the TikZ figures and use \includegraphics to add the externalised EPS files like the journal wants.

Do note though, that I'm not aware of any journal that directly accepts TikZ code for figures, so either you do it this way or write each figure into its own document with standalone to output the cropped diagram.

It depends on your journal. Many still require that figures are supplied as self contained (no psfrag of overlaid LaTeX) EPS files. On first glance this would appear to rule out TikZ, but in fact you can still use TikZ, and employing the external library with the appropriate extra bits for EPS (see Export eps figures from TikZ) will naturally spit out EPS for you. When it comes to submission time, you can comment out the TikZ figures and use \includegraphics to add the externalised EPS files like the journal wants.

Do note though, that I'm not aware of any journal that directly accepts TikZ code for figures, so either you do it this way or write each figure into its own document with standalone to output the cropped diagram.