What i mean is its pretty straight forward when to use them
Most Yoshi's don't know how or when to use eggs properly, even you. It's not as "straight forward" as you'd like to imagine.
Standing still while throwing eggs typically is a bad thing, unless they are on the ledge or off stage.
You can use eggs to predict movement, to cut off options, and to force an opponent to approach a certain way.
For example, when a snake is falling after using cypher high, you throw an egg vertical with high arc to cut off the option of them using a crossup, then pivot grab or dash grab depending on how close they come to you.
Against Wario, all they do is jump around so you wait til they use their first jump, then predict where they will second jump and peg them with an egg.
Against Marth, if he is on the ground, you will toss eggs short and low to prevent them from running under your egg arch. In the air, because of his bad air mobility and airdodge, you toss eggs straight at him. He either eats it or airdodges, in either case, puts him in a bad situation.
Against all characters, while on the edge, it is extremely easy to bounce the egg on the shield twice.
Against DDD, if you are facing an excessively grabbing DDD, if he is close, tossing an egg vertical with small arc will bait a grab from your lag, but they will take the damage from the egg.