In my D&D campaign, that I'm finally a player in, I have gotten to level 6 using a Warlock/Sorcerer build. Now part of what I was trying to figure with the build is, if it works on its way from level 1 to level 6. And it has some serious hiccups along the way.
The Beginning
I started off with Warlock 1, using the Celestial Patron. I chose my homebrew god, who encourages lying as a way to make people feel better about things, and said I was a Priest. I went 3 levels into this, until I got the subclass and chose Pact of the Tome. My eldritch invocation was to I could get ritual spells.
These first 3 levels were pretty typical warlock stuff, with some bonus action healing sometimes.
At level 4 when I got my first level of Sorcerer I chose Storm because of the bonus actions. I lied to everyone about getting hit by lightning and boom, I had storm powers.
I have to say, that the extra bonus action to escape was very useful. I was new to using a familiar (thanks to ritual casting) and was not using it to its full potential.
The Continued Mistakes
I then got to level 5 and messed up on prepping my spell slots for the day. The conversion is very unfavorable, and annoying to calculate. Not to mention you have to have a really solid conversation with your DM about this early set up. How many short rests can I take before I'm useless and have wasted too much of the day?
I didn't position myself well enough in some fights, and kept forgetting to save my slot for cure wounds with my familiar that's supposed to be doing the help action, but I didn't realize he could this whole time.
So I got up to level 6, where I can finally get Meta magic (I chose Subtle and Quickened). With my ultimate goal being Mold Earth and Flaming Sphere on enemies.
Future Planning
My current plans for this character aside from being a coffee lock, is to get a 6/6 split in Warlock and Sorcerer followed by an 8 level finalization into Trickster Domain Cleric. The final result being infinite Death Proofs.