English language readers usually read a comic starting on the top left corner and ending on the bottom right corner. The case is reversed if the manga is in Japanese and the reader is used to reading top right to bottom left.
you can organize your panels or small boxes in the same page into groups by leaving a wider blank barrier between each group of panels and the other.
you do not have to stick to traditional boxed organized in rows. You actually do not have to use boxes at all. You can separate different panels by having different backgrounds or patterns. You can also have your characters breaking the line of the panel in a more dynamic way.
think of every panel as a cinematic shot, and imagine it from the viewpoint of the camera. As similar to any movie, the camera does stay in the same place all the time. That is how you should draw your comic or manga.
Backgrounds and mood
matching the background to the mood of the story is always a nice and fun way to showcase character feelings.
Creative speech bubbles
not all speech bubbles are the same. You can experiment in different ways to draw speech bubbles, with no actual need for adding tails -the part that sticks out of the bubble and points at the character.