Planning for travel is my number one hobby. It is also my favorite part with the memories after the trip being second and the trip itself taking 3rd place.
I also am leaving for a tour in 4 weeks. I am taking the Paris city tour with 2 full days before the tour and one week after the tour on my own.
All of my flights are on Delta this time so I don't have to worry about any weight restrictions. But I don't want to have to carry more than I can handle so my backpack will weigh under 19 pounds and my personal item is just a messenger bag. I start looking at flights as soon as they are available. I pull the trigger when I see a price I am happy with.
I like to start planning 10-12 months before a trip. I start by getting familiar with each city or location. I read the RS guide, I read about the location on the internet and I watch you tube videos. Things start to come together organically. By 6 months I have a general idea about what I want to do in each location so I know how many hotel nights to book. I want to book hotels by 5 months out. For a tour of course, the itinerary is set but I am learning about the locations just like above and am deciding about pre and post tour stays.
As the trip gets closer I assign one week of planning for each individual day. I never stick with this, but it prevents me from over planning too early. So, I should have only 4 days of my trip left to plan out, but I actually have 7 days left to plan. I make a general outline of what I want to do each day. Each day has one thing that is a must do, a secondary activity and multiple tertiary activities. I don't usually end up doing all of these things, but I never have to worry about not knowing what to do once I am on the road. I like to be over prepared so I have metro paths figured out and written down or other transportation figured out and written in my journal. This decreases my anxiety once I am on the trip, especially when I am on my own. I also have venue opening and closing times written down for easy reference. I will start pre-booking events that I know require this. So far, I haven't missed out on anything because tickets were sold out. Although, I did not get my first time choice for my Eiffel tower summit tickets. I also do a little bit of restaurant (cafe) research in the areas I will be visiting so that I don't often end up in a tourist trap. I use Google maps to mark places and use my map a lot on the trip.
Early on in the planning process I start looking at the language. I learn general niceties for every country. Then I concentrate on learning some vocabulary, not so much for speaking but for reading. I feel more comfortable in a country when I can do a decent job of reading signs and menus.
I also make a list of food that I want to try. I may also pick a treasure hunt theme. For example, in Paris, I have the invader app installed on my phone and I am going to see how many Wallace fountains I can find and photograph. There are several Hemingway locations I want to visit. I want to see the in situ sculpture of Dora Maar by Picasso. I want to see some in situ works of Landowski. When I visit a museum, I have a list of a few pieces that I specifically want to see. I have read about the pieces and have some understanding about the historical context of the piece (otherwise I don't have much interest in art). In addition to a list of major sites I want to see, I have a list of quirky things that have caught my eye during my research.
I know for a lot of people that this much planning would take the fun out of everything. But planning is my fun. I never feel pressure to stick to the plan. The plan is there if I need it, but I don't HAVE to follow it.
Just typing this response has created a nice amount of dopamine in my brain!! Happy Travels!