I try to book my RUC's and GUC's (confirmed at ticketing) as soon as they show up in my account, for flights well into the future. I also try to use points for those flights further into the future since points decline in value over time, and cash can be invested.
And when/if I have spare RUC's, or I cancel one of those distant tickets purchased with points and the RUC/GUC redeposit, I look to re-fare tickets already purchased, and that also includes seeing if confirmed RUC space opens up on a main cabin ticket I have already booked.