The biggest yoshi specific trick is Double Jump Canceling, or DJC. Initiating a double jump, and immediately (or at any point during the jump, really) inputting an aerial results in the jump being cancelled, and your landing will have practically no lag. Better than L-canceling, if a tad riskier.
You can also hold the double jump during your aerial, and instead of the jump being completely cancelled, it will transfer the jump's momentum to the aerial. This is referred to as a Rising Aerial.
Those are the staples. If you want more specific things, like combos etc, check out the other threads. In general, you should read what's already out there, rather than making new threads.
