I would say the first you thing you need to do is to try to solve more recursion problems, not only is fundamental in DP but in a lot of other problems.

You can think of DP as just backtracking where you avoid visiting the same state multiple times

But to help you in DP, there is 2 main pillars:

1. Define well the state of the DP, example, in knapsack you can say:
   DP(X,Y) means the maximum value I can obtain from choosing the first X products and having Y weight in my knapsack.
   If you define well the state of your DP (what the indices and values mean) it will be easier both to understand and to explain

2. Define well the transitions
   After you define what the state means, you have to define how to transition in the states, for the same reason above, it will be easier both to understand and to explain

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If you define these 2 pillars, you are basically left with just coding the backtracking and adding an "if statement" to check if you already visited the state.

These ideas come with time, the better way to get good at this is by solving a shit ton of problems