Easiest way to create a custom tileset?

[Taycamgame]

What is the easiest way to create a tileset of any kind? Is there a way to open multiple files at once in paint.net (Where they would be in the same page then i could split them)? How were other tilesets created? Thanks.

[Emral]

Make a spritesheet. Look in the WIP graphics thread on the art board for references.

[HenryRichard]

Use FrozenQuill's Tileset Compiler and Separator to merge a bunch of blocks/BGOs/whatever into one image and edit them that way, then split them back apart. I typically make a sprite sheet like Enjl said and then copy the tiles over to the merged image.

[Emral]

The compiler tool doesn't work with alpha transparency, so I just open all tiles I want to replace and copy tiles from the sheet over one by one.

[Taycamgame]

Yeah, the main problem that I may have though is making blocks connect properly - so the lines on two blocks would touch rather than be pixels apart, how do I ensure that any tile set I create has the blocks properly connected without visual errors?
EDIT: Don't worry, i downloaded that program you sent the link to, works really well!

[FireyPaperMario]

Here's my method(s) of making a custom tileset in SMBX:

• Method 1: Use a basic pattern for your tiles (Zigzag, checker board, polo, polka dots, etc.)

• Method 2: Create it from scratch (It might take some time to make a original pattern..)

Hope that helps!