Most (Emphasis on MOST) flash games utilize a bit-shift algorithm.
For the most part, it usually follows the (X•8)+6 algorithm (Nearly ALL newer Flash Games use this Bit-Shift, I suggest starting with this first. Obviously, using Cheat Engine on a flash game in which your progress is saved onto a server won't work); where X is the face value you're looking for. The alternate algorithm is just X•8 (Which is generally what older flash games use).
If you're looking to use Cheat Engine in RPG Maker games, the usual bit-shift algorithm is just (X•2)+1.
Just remember it's going to take a few value searches to resolve the final memory address that you're looking for, and that you MUST put your desired value into the bit-shift algorithm as well, otherwise Flash or RPG Ace/VX will crash out.
EX: Say you want to change your gold value in a flash game to something stupidly high, like 999,999. You're going to have to plug that number into the (X•8)+6 or just X•8 equation in order to get the value you need to enter into the memory address (Which comes to 7,999,998 or 7,999,992 depending on which algorithm worked). Always double-check your math before you enter your final value, or else Flash will crash and you'll have to refresh the page to get the game working again if you make a typo with the final value.
When it comes to RPG Ace/VX games, you're going to run your desired value into the (X•2)+1 equation to get the actual value you'll need to enter. Most of the time, the highest gold value you can attain in these games is 99,999,999. Running that into the equation, your actual value becomes 199,999,999. Coincidentally, you can also do this for inventory items as well (Your actual value will be 199 as most of the time games only allow 99 inventory per item. Also note to be careful as if you decide to lock the value of a specific inventory item then transfer/sell all 99 of that item at once, the game will start getting screwy and will eventually crash.)
As far as RPG Maker games goes, most of the important values utilize the (X•2)+1 algorithm. This includes: Gold, other currency types, EXP, Bonus Stats (STR, AGI, DEX, WIS, INT, LCK, HP, MP), Inventory Items, Current HP/MP, and any kind of H Stat. Of course, if you're going to do mass stat / inventory editing, you're better off getting the appropriate RPG Maker save editor and making the changes that way.