1.

Be Your Own Tour Guide -      Curate your own tours by visiting paid sites & picking the destinations on their itinerary that appeal to you.  (They will already have them arrange in an order that makes sense if it's a walking tour.) A little bit of wiki research will fill in most of the tour guide's added benefits.  - I only pay for a tour if I wouldn't have access to the site or activity on my own...

2.

Prioratize your activities -      Look for free activities first, some of the best ways to get to know a new city is just to wander the streets and experience the local architecture and vibe. Churches are often free to visit, as are town halls, parks, shopping areas etc.

            When there is a spot you're interested in with an admission fee do your research ahead of time - look at images online to see if  the interiors, or add ons are worth the cost. I often find just visiting the exterior of a historical site is the interesting bit anyway, when the reason I am going is the architecture.   

3.

Don't Pay for a View -      Rarely do I find scenic views from the top of sites worth paying for - whether it's a church tower, ferris-wheel or just a tall famous building... Look for alternatives that don't charge a fee if you want that scenic photo op: Is there a public building with an accessible similar view?   A rooftop bar or restaurant in a shopping center? A scenic hill outside town? 

          Is the skyline even worth it? Maybe in Paris, but industrial cities like Berlin or Stockholm?  Probably not.

4.

Take Advantage of Discount Days -     Some Museums, for example, offer a free or discount day/ night once a week/ month.  Check ahead of time and plan your visit accordingly. 

5.

Use local Transportation -     The subway, buses, ferries and trains will be cheaper than cabs/ Uber ( especially if you take advantage of weekly discount cards.) Or even better, walk whenever possible - it's free, good exercise and a great activity to learn the city in itself.  Walking has allowed me to discover so many unplanned cool spots I never would have known to visit.

6.

Stay Somewhere You Can Cook -      Only eat out to experience a specific local cuisine you can't prepare yourself. Otherwise find the local grocer or market and cook, like you would at home. (This is easily accomplished with the help of a small kitchen kit so you aren't buying things like salt everywhere you go.) I actually find exploring the local corner store is a cool experience in itself- I like to try new ingredients unique to the location.

7.

Don't order Drinks or Snacks -        When you do eat out avoid beverages, especially wine (unless the drink itself is the unique experience you are going for.) Drinks are overpriced everywhere (it's where restaurants make their profit.) You can cut your bill in half by just ordering food.  So bring a reusable water bottle with you or a thermos of your own coffee/ tea to enjoy with your special pastry treat at the café. And always pack an apple or granola bar when going on long excursions so you don't have to buy a snack in an over priced tourist spot.

8.

Avoid Purchases in Touristy Areas -     Don't buy gifts, postcards or eat out across the street from any museum or tourist landmark. Not only will both objects and food be more expensive, they will also be less authentic, catering to tourist tastes, and not be a good indicator of the genuine culture of the city.

9.

Skip the Souvenirs Entirely -      They are rarely authentic, badly made and always overpriced. (You know they'll just uselessly sit on a shelf  when you get home...)  Photos are free and better memories anyway, not to mention you will only be adding to amount of stuff you now have to carry with you!

         I only make purchases when traveling if  1) it's truly unique or better made in my destination than it would be at home   AND    2) I would need it even if I weren't traveling. 

(Exceptions here may be art, if you are a serious art collector, or small gifts for others back home - but even then

be very picky about what & where you make your purchases)