I have never been one to "practice" hand flying. I will sometimes hand fly if I am bored or if I think I can do it better than the autopilot (it's not a great autopilot), but I don't do it with the intent of improving my skills. I won't specifically do it before I go to the sim for instance.
The following is just my observations from flying short haul jet transport ops, your milage may vary.
In my experience hand flying lowers the workload of the PF and increases the workload of the PNF. It also reduces the situational awareness of the PF. Although hand flying is a more natural and physically connected process I think it tends to focus your attention a bit more on what you are doing and reduces your ability to absorb what's going on around you. I know that contradicts my statement that it lowers the PFs workload. I suppose what I mean is that the PF has less to do but uses more of their brain to do it.
On the other hand the PNF workload is necessarily increased. Whether or not that matters depends on what their workload was to start with. If there is a lot going on, lots of radio instructions, lots of SOP chatter, in a busy unfamiliar environment then a small increase in the PNF's workload might be detrimental to safe flight. If the PNFs workload is low to start with then it doesn't matter if they've got a few more jobs to do. It all comes down to doing it at the right time and place.
In the space of a month and a half I found myself having to fly 6 full sectors by hand due to autopilot failure. I can't say that more practice would have helped. I didn't feel I was any better at it at the end of the flight than I was at the start of the flight. I did do a better job than the autopilot, but that says more about the autopilot than me.
Ultimately I think that those who tend to do a bit of hand flying here and there probably don't really need to. Those who avoid it are the ones who need the practice, and they're the least likely to get it.