These are my favourites/the ones I use most C:
1. Painting Brush: The Brush I use for most of my painting. It blends really nicely but you have to merge all your layers. It's nice and smooth and especially good for grass, fur, and small details.
2. Marker Tool: I mostly use the Marker tool for sketching, because it's soft and subtle and lines just turn out so much nicer <3 Also good for bushes or leaves. (fav.me/d6v9lg6 as shown here) Picture above is a really bad example of what it is capable of, sorry ahaha :L
3. Pencil Tool: Basically the same as the pen tool you automatically get in SAI, but with slightly changed settings for sharp, crisp and smooth lines C: I always use this one for lineart.
4. Marker Tool #2: Completely different to marker tool one. I use this one to lay down my colours while painting and not much else. It blends ok. Reason I like it though because its really good to lay down the colours you're going to use, as it's slightly see through, without making it look messy.
5. Acrylic Tool: I really need to rename my tools pff. Basically the same as the previous tool but with much better blending.
6. Fur Tool: Although I've never actually found a use for this tool (sigh) it'd be really good for fur and I love the way it looks //v\ just haven't found a use for it yet.
7. Water Tool: Ahaha wow I use this tool way too much. I use it for getting my shading to look softer at some parts, I use it for blurring, blending, lighting, adding effects ect. ect. Its one of the tools that comes with Paint Tool SAI when you first get it but I think the settings are changed a bit.
How to make new brushes in SAI
Most of you probably already know how to make yourself brushes in SAI, but here it is just in case. Right click one of the light grey, empty boxes underneath your tools, and select a tool base. (for example pen, brush, marker, acrylic, eraser) This will be the starting point of your brush. then just edit the settings, and give it a name C:
Feel free to make/use these C: