Honestly, this is pretty basic. It does take a few clicks to make sure you're sending in the right score but overall this is easier than setting up an account to SS. Let's begin.
Look at this small chart for Edna's Shadow as a World Challenge Game;
Notice that x_carlosjml_x and sergente__hartmann both have the same Hour's HS. Your first instinct is to simply send in a higher score than them. THAT IS A VERY BAD IDEA. More than likely, they want to stay below the review score. Your first step is to check the High Scores for the game you want to send a score in for.
Notice that 6, 7, and 8 all have the same score. This is pretty much a huge sign that says "DO NOT PASS THIS SCORE". Always remember to check and search for "Score Clumps" before sending a score. A "Score Clump" is usually 3 or 4 numbers that are identical. Simply search for that game's high-score list (In this case it was Edna's Shadow) and check to see where all the scores are piled up at. You may even be able to get a trophy if you stay below the review score and stay in the top 17. (for most games)
The next step is to check Youtube for a score TIME. The times is equally important as the score since you really wouldn't want to send in a score with a time of 2 or 3 minutes for a game that takes about 15 minutes to even get close to that score.
Notice that the times is 5:55. Not visible in this screenshot is that the score is at 2398. 2399 would be the score we wanted.
Now then, why can't I just send in a time of 5:55 (355 seconds)??? Mentioned earlier, most games on Youtube are for high scores and don't reflect normal gamer times. It is highly recommended to multiply the Youtube time score by 1.27 to 1.33. Using a factor of 1.27 your time would be about 450 seconds. This is more moderate and if you happened to get reviewed for some reason, it would be in your favor as opposed to having an incredibly fast time and high score.
A time of 450 seconds is roughly 7 1/2 minutes. Which seems much safer as opposed to 5 1/2 minutes. Play with times as you pick.
To create a custom list, just use sLAUGHTER's Score Sending List (Link in the Tools section) and modify the time and score like so;
GameID: 821 Score: 509-678 Time: 457-474 (YOU DON'T WANT TO USE THIS AS REVIEW SCORES WILL CHANGE OVER TIME)
*More to come plus cleanup*