A lot of this is conveyed via tone and nonverbals. There's a difference between the conventional rushed/confrontational "You're right, but" and what I've been doing, which is more like (Dark Arts ahead!):

"Good point, I think you're likely right." (thoughtful tone)

<intentional pause> (look up and to the left, furrow brow)

"Hmm." (vaguely surprised/"that's curious" tone, tilt head to the side, signal surprise via facial microexpression cues)

"I think that <my actual point> might also apply in some cases here. I can see situations where <my reasoning> would occur-- for instance, imagine if <my example> happened. In that case I think that model might explain what's happening here." (speaking slowly at first, with indecisive body language, then nodding and speaking quicker and more clearly)

<other person says something agreeing with me at least in part>

"Yeah, that's right. Now that I think about it that definitely seems like that's what's going on here." (confident/assertive)

When this works correctly, the person essentially tricks themselves into thinking that they came up with/helped develop the idea that I was trying to convince them of, which also has the useful secondary effect of making them a stauncher defender of this belief once they convert.

Note that this is dependent on situational factors and also (obviously) a Dark Arts type technique. Use sparingly.