This advice assumes that you're following a strict CKD during the week with a proper depletion workout on your last day. I suggest nothing shorter than 24 - 36 hrs. for proper glycogen recompensation (anything less than 12hrs. is a waste of time).
Split the carb-up period in half and during the first part consume very high GI carbs (in the form of simple glucose for example). The primary bulk of glycogen recompensation will occur within the first 24 hrs. of the carb-up phase (assuming adequate depletion has occurred).
As such, high GI carbs are ideal at the onset (since they are absorbed much more quickly than lower GI carbs - i.e., it takes less time to convert them to useable blood glucose which can feed the muscles).
Good food choices include: glucose/dextrose drinks, white potatoes, white bread, even jelly beans!! etc., the key is to keep food choices LOW fat. The CKD carb-up should not be treated as a CHEAT session (this totally defeats the purpose - which is glycogen recompensation!!).
Fructose isn't ideal (it preferentially refills liver glycogen as opposed to muscle glycogen) - but yah, it's not the devil, so a few pieces of fruit won't hurt.
Toward the second half of the carb-up period switch over to lower GI carbs (oatmeal, yams, whole wheat products, etc.,) or you risk glycogen spillover (i.e., fat gain!). The longer you play around with the diet, the easier it will become for you to tell when you've had your fill of carbs.
Note: ***AVOID FAT!! Make sure you keep fat very low during the carb-up phase (maybe 20-30g from EFA's if possible). The point is to recompensate muscle glycogen - and since insulin levels are going to be sky high - the last thing you want to do is consume fat at the same time (the job of insulin is "storage" - so high insulin levels and high fat intake equal disaster).