Good morning!
I hope everyone is doing well. If you feel tired after casting a spell and still feel the effects of it the next day, what is the best remedy? Since I am a baby witch, I am still learning how to ground myself properly. Now, I can drink cups of coffee etc., but what does everyone recommend? A bath? Sleep (Which is my favorite but I can’t cause of work haha)? A delicious meal?
Any feedback is welcome 
After I do spell work, I usually get something small to eat and drink, like tea or crackers.
Speaking of tea, I like to meditate and drink a mug before spell work (with herbs that pertain to whatever spell I’m casting). I’ve learned it’s a great way to prepare yourself physically, mentally, and spiritually.
If I still feel like my energy levels are off in the morning, I make myself a cup of coffee and say a quick prayer for energy.
Hope that helps a little!
I find grounding helps, especially meditation or some great grounding music while in shower or bath.
Self Care Self Care Self Care… 
Hi kasandra. It’s so funny that you asked this question today. I have spent this morning looking for the answer to that question for myself lol. I get extremely fatigued after some spell work and healings and if I do tarot reading for others. Thanks for posting a great question.
The more relaxed you are before starting the ritual, the better 
If possible, ground yourself before and after casting a spell!
Also, make sure you’re not only releasing energy into the Earth but also receiving it back at the same time in a flowing motion, as you breathe slowly and relax.
For extra effect, you can do this while you lean back against a tree or flat on the ground. Here’s a Guided Grounding Meditation 
I hope it helps!
I must say all these are beneficial tips for restoring your energy before and after spells. For me I tend to take a relaxing bath first, then take a short nap or relax while meditating before I cast. For me that holds alot ground is good as well and as @Francisco suggests
I make sure I do this while taking a shower or relaxing after spell casting I tend to snack on something crushy or even something sweet until my energy is restored.
That’s a great question @xphoenixsxreasonx, and I can see you’ve got some wonderful answers! 
For a few more ideas, I know there’s another forum discussion with some additional tips here: Feeling Tired After Spellcasting? Here’s Why- And How to Help!
My personal favorite treatment for exhaustion (both post-spellwork and mundane woes) is a hot and cleansing bath or shower 
The hot water and steam seems to cut right through mind fog! If that doesn’t work, then I try to be brave and turn the water cold 
. Sometimes a refreshing and chilly shower can work wonders for the mind and body (not to mention for silky hair and skin too!)
I hope you are feeling better if you were burned out- happy casting and blessed refreshing post-spellwork!
Love and Light
These are all great suggestions and I really second what everyone has said. I’d also like to just mention that you should practice your energy work a bit more. It’s actually one of the things that I feel we as witches and practitioners should constantly be practicing. It can help us with, as @Francisco said, release our excess energy but also make sure we’re not depleting ourselves. It is also very helpful in making sure that when you cast a spell, you’re not using all of your own energy.
Draw on the energies around you from the Earth, from the elements, from whatever you have. Raise energy by dance, music, or motion if you constantly feel tired or drained after casting a spell. Chances are you’re just depleting yourself. Afterwards, as others have mentioned, be sure to grab a light snack and something to drink. Rest if you need to (naps are great) but if not possible, just take it easy for a bit.