Some fairly common problems for L seat pilots first trying the R seat:
* the perspective is all 'wrong'. Aligning the aircraft with the rwy. gives a different picture. The first few times usually result in the a/c not quite being straight with the rwy. when the wheels touch. Bet you both tended to land on the RH side of the runway centerline...
* Not quite wings level flight. Again the sight picture is lopsided in a mirror image to the 'normal' seat view. You get used to the 'normal' lopsidedness of the cowling/panel/coaming when the wings are level. Jump into the other seat & now you have to deliberately reverse something you've spent many hours establishing.
* Altered muscle use ie you become habituated to using one hand to push/pull on the throttle & the other to do the equivalent on the column/stick. It can - but doesn't necessarily - lead to a situation where the habituated muscle usage is the incorrect one for the circumstance. Think of the a/c low on final. The normal response would be to add power (push with the R hand & pull with the left. Think what effect that will have if you're in the RH seat...
Or a bounce that needs a bit of power to cushion the landing. Same thing about the push/pull reversal.
The reversed control resistance/feedback can be a bit off putting as well. You have to relearn how much pressure is appropriate using your other hand.
* Slow to react to events that you normally do a lot faster eg emergency actions. Again, you tend to memorise the spatial relationship of all the switches, how to move your head/eyes/body to see & select the relevent things. In the other seat that tends to fall apart & it becomes a bit like the first time you did those things from the LH seat, having to hunt around to find where the things you want are... Knobs & buttons & switches won't fall easily to hand. Nor will finding where to look for information, which leads to...
* ...More difficult to read the instruments: A lot more parallax error that needs compensation from the pilot. Makes flying accurately more difficult at first.