I bring topo maps on all but the most familiar routes. Their primary purpose is for my safety regimen, but they offer the bonus of considering spur routes and alternate trails if I come across them. I was never happy with the USGS maps as they are oversized and often covered large areas that I was not interested in. I then cut them down to the areas I needed so as to be easily folded into my map bag. I felt the cost was too high for the amount of map I was left with. This doesn't even consider the delay in procuring maps if I couldn't find them in-stock at my local gear store.

 

I began reading about custom topo maps a few years ago and was impressed with Andrew Skurka's method that he details on his website. I access Caltopo for maps in the U.S. and Ordnance Survey for maps in the U.K. Both sites allow me to frame the area I'm interested in and save them as 11x17" PDFs (A3 size for Ordnance Survey maps is close to 11x17"). I have memberships to both of these services and find the annual fees to be great values. I typically make topos at a 1:24,000 scale. I then upload them to a printing service (there's a FedEx shop near me) and pick them up at my convenience. I do one-sided printing (one map per piece of paper) as I often write notes on the backside before I head out. Full color prints cost about $1.25 inclusive of tax. You can lower cost-per-map further if you do two-sided printing.