There's signaling effort (especially to yourself), and then there's effort. You want to reward effort but not signaling effort.

Often one will make a cursory attempt at something, but with the goal of signaling to themselves or others that they put in effort or tried rather than doing what was most likely to accomplish the goal. This leads to statements like "I tried to get there on time" or "I did everything I was supposed to do." That's excuse making. Don't reward that.

Instead, reward yourself to the extent that you did that which you had reason to believe was most likely to work, including doing your best to figure that out, even if it didn't succeed. Do the opposite if you didn't make the best decisions and put forth your best efforts, even if you do succeed.

The danger is that effort is much easier to self-deceive about than results - and the people who need this the most will often have the most trouble with that. Not enough attention is paid to this problem, and it may well deserve a top level post.