If you plan to use flour, make sure your baby has been introduced to wheat. Wheat is one of the Top 8 allergens, so depending on the age of your child, you may want to hold off for a while.
Really, there's no need to thicken baby food or to try and make it look like the store bought stuff.
For veggies, just steam and puree or cut in cubes if baby is old enough for finger foods.
For fruits, just use ripe, soft fruit and puree or cut in cubes.
For meat, I waited until my son was old enough to eat finger foods, around 8 months, before introducing meat. Then I would just cut up pieces of plain chicken or beef and he'd feed himself. No need for sauces. He loves it.
And it's a lot neater without sauce, in my opinion!