As Mr.Sou said grabs are important too...
I didn't go to smash school for eight years and intern for three to be called Mr.
Hichez, you need to learn that the ledge is your friend. Lucario's options from the ledge are anything but limited. Its important to mix them up and know when certain options are safe, but there are multiple options for every edgeguarding location that your enemy takes.
Every character's basic ledge options are: roll, stand, get-up attack, jump, or drop. Lucario has these and more, if you consider how many possibilities there are from a ledge-hop or a jump.
Jump->airdodge (usually fastfall): good for baiting your opponent into the air and then safely re-taking the stage
Jump->Dair: for a dumb opponent who stands at the end of the stage
Jump->DJ: good for staying high above the opponent if they dont chase you into the air (follow this with anything)
Drop->ES: your favorite, lol. good for resetting your invincibility frames, properly timing an edge-hog kill, or dodging an attack aimed at the ledge.
Drop->aerial: for harassing an opponent attacking you offstage or trying to recover.
Drop->shark: an attack from the ledge done without Lucario returning above the stage. best option is Up-air, which can go through the ledge on maps like FD and SV.
Drop->cling: on FD and a few other maps. you can fall into a wall-cling and then wall-jump over the edge onto the map, often with a back-air.
Ledge-hop: dropping from ledge and using double jump to recover onto the stage.
Ledge-hop->aerial: great for varying your recovery onto the lip of the stage. You can even land a full Fair->fastfall Nair->FCAS combo if you time your jumping fair correctly.
Ledge-hop->(FC)AS: good for backing up an opponent standing far from the ledge with an attack.
Ledge-hop->Walljump: On FD, BF, Yoshi's, PS, and a few other stages, you can ledge-hop back into the ledge, and if you do it quickly enough you will walljump off the ledge and end up higher out over the map. I like to use this as a mixup and b-reverse an AS charge at the peak of the jump, giving me a charge while moving towards the stage over my opponent and also facing them.
Ledge-hop->wavebounce ASC: if you wavebounce with aura sphere while jumping over the ledge, you will move your charging aura sphere directly into your opponent while facing away from them and the ledge. few people expect this, so it can lead to a nair/dair out of shield to punish. requires balls...and luck.
Ledge-hop->double team: not recommended. Marth's do this with their counter all the time, but we usually end up off the map with our counter-attack when done improperly. can work sometimes, but its dangerous.
I probably even forgot some, but my point is that the ledge is very important and so are the options it provides. Keep all of these at your disposal and vary them as much as you can. Just keep in mind, Lucario is very gimpable and any time you want to spend on the ledge deciding which option to use should be done within your invincibility frames. Don't linger or become predictable on the ledge, or a skilled opponent will always make you pay.