Building a trail of memories with keepsakes.
If you plan to buy souvenirs as wonderful reminders of your travels, it could be an initiative to start a collection of sorts (I have fridge magnets since they are cheapest).
Having a theme gives you something to look out for while travelling and a feeling of satisfaction that you have picked it up. Souvenirs do not have to be even bought. My oldest daughter collected sand that she would put in little glass bottles back home, labelling each with the name of the place (obviously I taught this one very well). One can do similar things with smooth large flat pebbles that will come in different hues. Just write the name of the place on one side, and month and year on the other side.
You can start a collection with what you could already have had, by default due to travelling. For instance, collecting airplane boarding passes are my favourite (since they are free and even beat the cheap fridge magnets).
They record the details if ever one wants to refer back to the time and place of the holiday, years down the line. You can stick a photo of any particular highlight of that trip at the back of the boarding pass. You can either spiral bind all the passes later or just store them in a photo album.
If you love beer, then just collect all the unbent bottle caps (assuming you will try the local beer and not feel embarrassed to ask for the bottle cap). Look out for the local matchboxes, stamps from the grocery shops or supermarkets. Get the drift?
For taking gifts back home, a souvenir will work or some local shopping from the supermarket. A friend of mine visits the local shops and buys ingredients that are unique to the place to try out in the kitchen back home. Still better, you could pick up all the ingredients locally and pack in the recipe for friends and family who would love to try out new cuisine.
Typically, one will find the usual cost-effective souvenirs everywhere including markets where they are cheaper. Avoid buying them at the stalls close to the tourist attractions unless you really like something unique. You can decide to make a collection of bottle openers or small décor pieces. Ultimately it is important that you find a souvenir to make your holiday memory concrete, personal and special.