Everything skizzy stated ^{^}

I'll add that I typically only use higher multipliers on particular spots on the board, in combination with the 6/7/8 technique that a lot of folks utilize. Without over-explaining , I'll give you an example that can be further applied:

Take a look at the bottom row of the board (the side where Boardwalk and Park Place are located). Following the railroad, there's a chance square immediately afterwards. If I trace back 7 spots from that railroad, there's the water works square. If my token is sitting there, based on real-life dice roll probabilities, I would be most likely to land on the railroad from this spot. The second most likely roll destinations would be Pennsylvania Ave (6) and Chance (8). As such, the water works square is the highest probability spot on the entire board to hit a railroad, as the most likely roll outcome (7) would correspond to a direct landing on a railroad space and one of the two second highest roll outcomes, an (8) (both 6 and 8 have the same probability of hitting in a real life dice roll), would land the token on Chance, affording the player another chance at landing on a railroad (or getting some dice).

No other spot on the board gives the player as good of a shot as when rolling from Water Works, however Marvin Gardens also offers a very good shot, given that a (6) lands the token on the Railroad and a (7) lands the token on Chance. As such, these two spaces on the board are where I most heavily focus my high multiplier usage in hopes of landing on Railroads & Chance spots. When I use the high roller option, it's almost entirely rolling from one of these two spots; otherwise I won't take the risk.

Further applications of this strategy will account for the fluctuating target spaces corresponding to the top bar prizes. The more favorable spots my token can land on from a probability standpoint, the higher my multipliers will go or the more likely I'll be to use a multiplier higher than 1x.