This is a personal favourite (when I have the time) to do when I get home from my trips. Unleash your inner creativity with washi tape, glue and scissors as you record experiences in a multitude of ways. Save every ticket, random package, and receipt, and annotate around your pictures and souvenirs. Add stickers and written mementos so you remember exact moments, opposed to whole days, and reminisce retrospectively as you create. The only cons are the time taken, and your own inner perfectionist coming out for a spell.
I have never been one for journaling, but on solo travels I keep family and friends updated through daily and weekly emails, which can be as broad as my general adventures to in-depth detail about each day and embarrassing cross-cultural mishaps. Choose to write online or by hand, for an audience, your future self, or keep your diaries a secret. This gives detailed accounts to your travel, as opposed to brief snapshots.
This could be through in-depth travel vlogs or one-second-a-day style apps which record highlights only. It all depends whether you feel comfortable editing or recording yourself in public, but it is an easy way to showcase your time abroad. If you are stuck for inspiration, there are plenty of vloggers you can check out online.
Whether this is via daily posts on Instagram, or looking like a pro and taking millions of photos on a DSLR, there are multiple ways to take, share, and access photos of travel. One of my favourite Instagrammers takes photos with toy dinosaurs at every place, while others choose only to photograph food, and some simply selfie everywhere they go. Photos can then be blown up on canvases, stuck on photo walls, put in photo albums, and returned to whenever someone asks to see evidence of your trip. There are also virtual scrapbooks you can create by dropping photos into preselected templates which, although takes the creativity out, makes it easier to combine your travel photos and have them for the future.
Send postcards either to yourself or family about your travels. Pick picturesque landscape postcards, funny postcards, or plain ones and use them to reminisce when you get home. Often older relatives have postcards from decades ago lying around, look at them for inspiration.
Some people collect certain things from every place they go- be it corks kept in vases, fridge magnets, bus tickets, Starbucks city mugs or coins. Find your thing and start a collection.
Use the scratch off maps or pins and tags recording the dates of visit and where you travelled. You could also sew your trips onto a map (from your flight to various city travels) in different colours or stick a photo next to each country you have been to. Stick the map up where you can see and let the memories flood back.