I travel for work too (way more than I like to) and have some methods that I use for my travel.

Just because you get 5 X points doesn't mean Penfed is good. Did you actually see the rewards and know what you want. I have 200k+ on Penfed and there is hardly anything I want apart from the low cost airline tickets (they usually discount by 15-20% taking 1point=1cent)

For car rentals, search for the thread Q2 car rental promo (Q3 will be there when we are closer to Q3). You will see different promotions for car rentals. I usually book Avis (for miles on some airlines usually 3k) or Hertz (for points to get car rentals and status).

Other than that, for hotels too I chase the promotions. I usually get the Hilton status in the beginning of the year and then chase the promotions (unless a promotion is sweet enough for me not to stay at hilton).

In the end use cashback sites (I can refer to you. PM me). I end up getting around 100-150 each quarter using the sites (I forget to go through the cash back site most of the times since I am booking at the last minute and there's so much to do)