Familiarize yourself with the mangaka's works
So, you finish a really great manga. "OMG. This is the best!" You declare as you snap the book shut and set it on your shelf with a satisfied smile. But, that smile soon fades, and an emptiness sets in. A cold sweat. Now what do I read? You ask yourself. The answer is simple.
Read the rest of the mangaka's works.
A simple trick from your non-manga reading friends is to read another book by the same author. Now, granted, it's a smidge harder to do with manga than with those regular hardcover and paperback novels. Not all of a mangaka's works get licensed and put on the shelves. Some mangaka only have one work out there, but for the mangaka who do have multiple works licensed (and there are plenty), please for the love of Tezuka just start there first. Even if the next work isn't quite the same as the one you've read, it's still worth going through the catalogue.
Reading a bunch of the mangaka's works has benefits. One, you connect with the mangaka and their works on a much deeper level. Two, for mangaka that write across multiple genres, themes, and demographics (Clamp easily comes to mind), going through the catalogue is an easy way to challenge yourself as a reader. You can read stories outside of your comfort zone just by going through a mangaka's catalogue. Three, it's just a fun and easy way to find the next manga you'll love.
So, go through the catalogue. Check out the rest of the mangaka's works, and read the ones that sound interesting to you. Below is a list of authors and artists with multiple works under their belts to get you started.
Gido Amagakure
A Galaxy Next Door
Sweetness and Lightning
All published in print/digital by Kodansha.
Moyocco Anno
Flowers & Bees (out-of-print; VIZ)
Happy Mania (out-of-print; Tokyopop)
In Clothes Called Fat (Kodansha/Vertical)
Insufficient Direction (Kodansha/Vertical)
Memoirs of Amorous Gentlemen (digital-only; Crunchyroll)
Sakuran (digital-only; Kodansha)
Sugar Sugar Rune (out-of-print; Del Rey)
Naoshi Arakawa
A School Frozen in Time
Farwell, My Dear Cramer
Sayonora Football
Your Lie in April
All published in print/digital by Kodansha.
Inio Asano
A Girl on the Shore (Kodansha/Vertical)
Dead Dead Demon's Dededede Destruction (VIZ)
Downfall (VIZ)
Goodnight Punpun (VIZ)
Nijigahara Holograph (Fantagraphics)
Solanin (VIZ)
What a Wonderful World (VIZ)
Scarlet Beriko
Fourth Generation Head: Tatsuyuki Oyamoto (SuBLime)
Jackass! (SuBLime)
Jealousy (SuBLime)
Minori's Hand (digital-only; Renta!)
Nagisa Furuya
My Summer of You (Kodansha)
S to N (digital-only; Renta!)
The Two Lions (Seven Seas)
Matsuri Hino
Captive Hearts
MeruPuri
Shuriken and Pleats
Vampire Knight
Vampire Knight: Memories
Wanted
All published in print/digital by VIZ.
Aki Irie
Go With the Clouds North by Northwest (Kodansha/Vertical)
Ran and the Gray World (VIZ)
Junko
Kiss Him, Not Me (Kodansha)
Mr. Mini Mart (Juné)
Return of the Prince (Juné)
Star Crossed!! (Kodansha)
Aya Kanno
Blank Slate
Otomen
Requiem of the Rose King
All published in print/digital by VIZ.
Sayaka Mogi
Red Riding Hood's Wolf Apprentice: False Stars (Glacier Bay Books)
Red Riding Hood's Wolf Apprentice: Final Testament to the Moon (Glacier Bay Books)
Red Riding Hood's Wolf Apprentice (digital-only; Kodansha)
Nagabe
Love on the Other Side-A Nagabe Short Story Collection
Monotone Blue
The Girl from the Other Side: Siúil, a Rún
The Wize Wize Beats of the Wizarding Wizdoms
All published in print/digital by Seven Seas.
Takeshi Obata (artist/illustrator)
All You Need is Kill (story by Hiroshi Sakurazaka)
Bakuman (story by Tsugumi Ohba)
Death Note (story by Tsugumi Ohba)
Death Note Short Stories (story by Tsugumi Ohba)
D.Gray-man Illustrations: Noche (print only; art book; contains a Tsugumi Obata Q&A)
Hikaru no Go (story by Yumi Hotta)
Platinum End (story by Tsugumi Ohba)
Ral Grad (story by Tsuneo Takano)
School Judgement: Gakkyu Hotei (story by Nobuaki Enoki)
All published by VIZ.
Tsugumi Ohba (writer)
Death Note
Death Note Short Stories
Bakuman
Platinum End
All of the art is by Tsugumi Obata. All of the series are published in print/digital by VIZ.
Yoshitoki Oima
A Silent Voice
Mardock Scramble (story by Tow Ubukata; art by Yoshitoki Oima)
To Your Eternity
All published in print/digital by Kodansha.
Natsume Ono
ACCA 13-Territory Inspection Department (Yen Press)
ACCA 13-Territory Inspection Department P.S. (Yen Press)
Danza (Kodansha)
Gente (VIZ)
House of Five Leaves (VIZ)
La Quinta Camera (VIZ)
Not Simple (VIZ)
Ristorante Paradiso (VIZ)
Tesoro (VIZ)
Setona Mizushiro
After School Nightmare (out-of-print; Go! Comi)
Black Rose Alice (out-of-print; VIZ)
The Carp on the Chopping Block Jumps Twice (Seven Seas)
The Cornered Mouse Dreams of Cheese (Seven Seas)
Marimo Ragiwa
Baby & Me (VIZ)
New York, New York (Yen Press)
The Vampire and His Pleasant Companions (story by Narise Konohara; art by Marimo Ragiwa; Yen Press)
Those Snow White Notes (digital only; Kodansha)
Kei Sanbe
Erased (Yen Press)
For the Kid I Saw in My Dreams (Yen Press)
Island in a Puddle (Kodansha)
Kamiyadori (Tokyopop/out-of-print; VIZ/digital-only)
Testarotho (out-of-print; CMX)
Takako Shimura
Even Though We're Adults (Seven Seas)
Sweet Blue Flowers (VIZ)
Wandering Son (dropped by Fantagraphics after 8 volumes)
Aya Shouoto
The Demon Prince of Momochi House (VIZ)
He's My Only Vampire (Yen Press)
Kiss of the Rose Princess (VIZ)
Tamekou
My Androgynous Boyfriend (Seven Seas)
Lala's Married Life (digital-only; Animate International)
Ema Toyama
Aoba-kun's Confessions (digital-only/digital-first)
I Am Here!
I Guess I Became the Mother of the Great Demon King's 10 Children in Another World (digital-only/digital-first)
Kamikamikaeshi (digital-only/digital-first)
Manga Dogs
Missions of Love
Vampire Dormitory
All published by Kodansha.
Yumi Unita
Bunny Drop (Yen Press)
Slumbering Beauty (Seven Seas)
Mika Yamamori
Daytime Shooting Star (VIZ)
In the Clear Moonlit Dusk (Kodansha)
Tsubaki-chou Lonely Planet (Yen Press)
Fumi Yoshinaga
All My Darling Daughters (VIZ)
Antique Bakery (out-of-print; Digital Manga Publishing/DMP)
Don't Say Anymore, Darling (out-of-print; Juné/DMP)
Flower of Life (out-of-print; Digital Manga Publishing/DMP)
Garden Dreams (out-of-print; Digital Manga Publishing/DMP)
Gerard & Jacques (out-of-print; Blu)
Ichigenme...The First Class is Civil Law (out-of-print; 801 Media/DMP)
Lovers in the Night (out-of-print; Blu)
Ôoku: The Hidden Chambers (VIZ)
Solfege (out-of-print; Digital Manga Publishing/DMP)
The Moon and Sandals (Juné/DMP)
Truly Kindly (out-of-print; Blu)
What Did You Eat Yesterday? (Kodansha)
(Digital Manga Publishing had way too many imprints back then, and they are still just as confusing today as they were back then.)
Kaori Yuki
Alice in Murderland (Yen Press)
Angel Sanctuary (VIZ)
Beauty and the Beast of Paradise Lost (Kodansha)
Demon from Afar (Yen Press)
Fairy Cube (VIZ)
Godchild (VIZ)
Grand Guignol Orchestra (VIZ)
The Art of Angel Sanctuary: Angel Cage (art book; out-of-print?; VIZ)
The Cain Saga (VIZ)
Naoki Urasawa
Finally, I'll leave you with this great video about Naoki Urasawa by mangatuber The Omnibus Collector. He gives a rundown of Urasawa's works, and he makes an excellent case as to why you should check them out.