Use high protein, high fiber flours. Oatmeal, garbanzo bean or other bean, sweet sorghum and teff are a few examples. Rice and coconut can be used, but these are drier flours with little fiber, so can make the baked goods tough or crumbly and very dry if used alone.
Use more than one flour for a recipe, preferably at least three. I always use four different flours.
Double the amount of baking powder or baking soda used in the recipe.
Always use both baking powder and baking soda in every recipe. Double the amounts as above.
Add a tablespoon or two of potato starch to the flour mix.
Add 1 and 1/2 to two times the amount of liquid to the flour mix. If the result is a sweet, use "liquid" that has a lot of fiber. I often use applesauce or liquefied bananas instead of a milk substitute. I even use applesauce when making cornbread and then don't add sugar.
Always add a generous amount of oil to the flour mix. I usually add a scant 1/4 cup of canola oil or melted coconut oil. Olive oil has too strong of a taste for most things.
For egg replacement I use EnerG Egg Replacer or VeganEgg, sometimes both! Both need to be dissolved in liquid. EnerG I dissolve in the applesauce. VeganEgg I use less water for baking, as they suggest.
Let the mix set for five minutes.
Finally, bake for longer in a lower temperature oven. I bake most recipes 15 to 20 minutes at 325 to 350 degrees.
Now give these tips a try and tell me what happens!