All the approaches have advantages and disadvantages. For example, @Team9nine's photo approach show both him and the bass, which is good, but looking at his second photo above, that bass goes from the top of his head to the top of his thigh. At first glance, it appears to be three feet long or thereabouts.
When I used to have a fishing partner who could take a photo of me with a bass, I put my elbow behind my head so that the bass would be right beside me to provide scale. I understand that I'm in the minority here and that a bass displayed this way looks small compared to a bass with extended arms. You can see that the bass below goes from near the top of my head to mid-torso. At first glance, it's a considerably shorter fish.
I love having photos, but as Alex noted, I love my mind's memories even more. Even though I caught the bass above a decade or two ago, I could take you to the exact spot where she hit, as long as you were willing to launch just above a waterfall, paddle across one lake, bulldoze through the current of a narrows, wind through a reed field, and then cross another lake. There's an even better lake beyond the one above, but it takes crossing a couple swamps and four sets of rapids. Oh, I wish I were young enough to reach such places still.