This is missus, one of the juniors and our bikes, fully packed up somewhere in Norway. We carry two Coleman tents, one is an older igloo model which houses 3 persons comfy and 4 with love; the other one is a Coleman Phad for two persons. Travelling in Europe means travelling in the rain sometimes and we have found that a real apsis is needed in front of the tent´s entrance, where you can park your boots which you may need at night...
Since we´re taking weeklong paddle trips as well, we´re used to pack small and have somewhat optimized gear. We´ve even managed to not stow gear onto the lids of the panniers :-) Note that my wife carries the smallest panniers available from Touratech, some 20 liters only.
Everyone "owns" one pannier and needs to stuff in it the personal Therm-A-Rest, rolled up and compressed. The regular TAR will do perfectly, if you need double- or triple thickness, buy a Goldwing and a trailer. Everyone will have to take care of a small (soft pencil case) bag of toiletries, a towel and a personal Mini MagLite LED, and personal effects such as books, Gameboy
and the like. The biggest pannier additionally holds food and the Trangia stove, the second-biggest pannier takes up the emergency drugs (Penicilline etc).
The big Ortlieb sack on the Africa Twin holds four sleeping bags, stuffed in as they come and not(!) in their individual packing/compression sacks. The yellow Ortlieb (size Medium) holds both tents and accessories including a lightweight hammer. As with the sleeping bags, the tents are stuffed in there as they come and not folded or else, as this is easiest to compress. Note: Don´t buy tents with windows, as the windows hate to be crumpled, even the new "soft" windows. Use Ortlieb bags for tent and sleeping bags as they will double as overnight storage room; stuff your MC gear in them and park them outside of the tent. If you need to purchase the top-loading bags yet, get the ones with the air valve - they are easier to use when you need to compress four sleeping bags in them. Take one extra bag and a set of straps with you: It´s additional storage space on the pannier lid where needed after shopping or at a variety of other short-notice occasions.
Necessary tools including tire irons, spokes, etc. are kept in the plastic roll mounted to the engine guard of the Africa Twin; a small extra petrol can is attached to the back of a pannier. 0.5l of engine oil are kept in a canister under the seat.
Use motorcycle gear which is multi-purpose. Cheap MC boots will take their toll, as you will hate to walk in them and thus you need to stow a pair of hiking shoes. Perfect boots (I prefer Daytona) will let me stroll through town without feeling uncomfortable; additionally I pack a pair of Wolfskin sandals, which carry me everywhere else. Use multifunctional trousers with zip-off-legs, so you won´t carry two trousers for sun and rain. One fleece pullover (doubling as inner layer of the MC jacket if it´s cold), two T-shirts (I tend to buy some memorabilia T-shirts anyways at some point in time), a towel, two sets of underwear, a second set of comfy socks for the MC boots and a tube of washing powder. Long haul travel is not a catwalk - and you will need to allow missus a little extra space for the one extra shirt and towel and nail clip and ... you get the drift.
The tank rucksacks take the daily and quick access-stuff - Leatherman tool, Zippo, maps, travel guide, first aid kit, camera, bottle of water, lashing gear for ferries, passports, wallet etc.
The Touratech bags left and right of the Africa Twin tank take 2 sets of rain gear each and soften the impact if you drop the bike :-)
One basic rule: Everything has its assigned place. If it´s not there, no need for a search - we´ve lost it.