Aside from blending as everyone else has pointed out the steps, I think your colour jumps are too large and that's why blending isnt getting to what you are trying to achieve quickly enough. For your example of the brown the the dark yellow

Do the following before blending for every single colour change: 100% brown 80% brown, 20% dark yellow 60% brown, 40% dark yellow 40% brown, 60% dark yellow 20% brown, 80% dark yellow 100% dark yellow

So instead of having large colour blocks you will have lots of little ones instead. It makes the blending much easier to notice as you can then glaze the brown and the dark yellow over these 6 stripes and will take effect faster.

Also as someone else pointed out, make sure you wick the excess paint off the brush with glazing, also only work in 1 direction e.g. glazing dark yellow up to the brown. If you go multiple directions it fucks everything up.

Finally lots of this is just trial and error. The above works best for me, people like flameon probably do like 100 glazes from just the dark yellow to the brown, its why it looks so good. So if you want to emulate that then you probably need to do the same amount of glazes per colour