When leaving for a motorcycle road trip of any significant duration, it is easy to prepare the for the obvious eventualities. Money, clothing, simple tools, and prepping the bike itself are all important, but so are the little things that can only be learned and taught from experience.
I don't have many of these tips, but someone may find this short list useful directly or indirectly.
Maps or preloaded cell phone
I haven't carried a paper map for a long time, and rely on my phone to get me through unfamiliar country. That doesn't work if the area is remote and has poor or zero cell coverage. I suggest either packing a paper map or preloading maps of some sort on your phone. The official Google Maps app has the capability to download and cache moderate amounts of roads and place names. Although recently Google updated it so can generate directions while offline, with a map you can come up with that on your own too.
There are other apps that can generate offline directions, but while a couple are decent the majority don't work the way they should. Test extensively before relying on one.
Maps on a phone are great right up until the phone dies. If the motorcycle doesn't have a 12V power outlet the only option is to prepare for this in advance. Bring a portable USB charger or buy spare batteries for your phone model. It should go without saying that every single one of these should be charged before departing, and at every opportunity thereafter.
International/Roaming Cell Minutes and Data
If travelling in another country or even just near the border, having a second SIM card that can connect there can be worth having. A SIM card is a tiny thing but not having one when you need one can be a frustrating experience. Also, remember that minutes and data will cost a fortune when roaming, and will either deplete or stretch your budget depending on your contract.
Moving on from technology, engine noise is music and so is the wind, but even the greatest concert will become repetitive or painful after time. Cheap earplugs from dollar stores get the job done, but thankfully I have experienced custom moulded earplugs and the difference they make. They are often sold as "musician earplugs".
These plugs require a trip to an audiologist and cost somewhere in the $100-$200 range per pair. That is well worth it considering how long they last (years) and the non-linear response. There are different snap-in sound filters that cut down specific frequency bands by specific amounts. Nearby cars in traffic will sound the same as though the plugs were not worn, but lower notes such as tire rumble and higher notes such as wind will be reduced.
Most if not all helmets are available with swappable clear and shaded visors. While the shaded one may be great during the daytime, if you look at it closely it will invariably have a warning stamped on the side that says "for daytime use only". Not only is it likely illegal to use such a visor at night, it also just doesn't work. It is easy to forget to pack a clear substitute when leaving on a trip at high noon.
Kleenex or paper towel will do, anything that can meet the inevitable need for them. Whether it's a dirty headlight or a runny nose or a muddy turn indicator or even an oil check, having something other than grass at hand is worth the extra space it takes to carry it.
Good for keeping a phone and GPS dry. Even a plastic grocery bag is enough, and that has the bonus of not being expensive, so tossing some waste or laundry into it isn't going to be painful.
Protect Neck and Hands
Air is denser than it seems, and in addition to being the largest factor in fuel economy, air resistance can also be rough on exposed skin. At speed, skin on hands and the neck can become irritated, so protect them with gloves and a sport undershirt with a high collar.
As usual for outdoor activities, dress in layers. Driving through terrain with varying elevation can result in a hot sunny day beside a lake turning into a chilly winter drive past snow in the ditch. Or vice versa.