Select a route that reflects a sufficient ratio of climb to descent/recovery time. For example, Alpe du Huez might be 60-70 up and 15 down (4:1) versus Ventaux at 100 minutes up 20 down (5:1). I've completed the challenge on each and found the shorter/more frequent recovery periods on Alpe to be less grueling.

Power/effort management is critical--avoid overdoing it early. I spent the majority of my pre-event training just doing 2-3 hour climbing sessions at 50-60% FTP in order to get used to NOT digging in on higher gradients

Plan on using MULTIPLE top quality bibs. Top bibs might remain comfortable after 8-10 hours outdoors even on a hot day, but indoor riding generates more sweat and usually less movement on the saddle. Fresh bibs provide a nice mental boost too.

Plan, plan, plan!  Pre-ride the hill so you can plan the number of reps required to achieve that iconic number, 8,848.  Plan your training, plan your gearing, plan your rep pattern, plan your nutrition and fluid intake, plan where you are going to the toilet, plan what your going to do if you have a puncture, have a mechanical, plan changes of clothes, plan for rain, plan for sun, plan how you are going to deal with the monkey that sits on your back after 6,000m, when you still have 5 or 6 hours to go! 

Break the ride down…However many reps you need to do to Everest, it’s going to be a long day.  For the average person (like me) probably somewhere between 18 and 24 hours.  That is simply too daunting to consider when you are sitting on the start line at 4am.  So break the down - how many reps between breaks do you plan to do?  When is breakfast?  When is lunch? When is dinner?  When is the post ride beer?!  How might the rep pattern change as the day progresses?  That way, all you really need to think about is the set of reps that you are riding and the rep itself.  

Measure and measure again...Everesting is all about the reps complete and the meters climbed.  Most of us will be riding with a decent head unit mounted on the bars. The trouble is these head units can be unreliable - they rely on barometric pressure changes to measure elevation change.  But weather and temperature impacts pressure, so the meters climbed that you see may well not be the meters you have actually climbed!  Given this, it’s actually better to rely on the number of reps (yes, you need to know how many meters vertical each rep is worth).  So, assuming as part of your planning, you rode the hill, you will know the length of the segment, but more importantly, the precise length of each repeat (up and down, or down and up, depending on where your base camp is, including the turns).  You then simply set a lap on your head unit to that distance and it will automatically counts your reps!  Oh, and the other thing to consider is if the head unit is reliable. For my last Everesting I ran two…!