Question about companion planting
 

Hi, how are you?
I started to do companion planting recently. Yesterday, I planted
both beans and corns on the rows next to each other. However, I did
not know how closely I should have planted them together. In my case,
I planted them about 25 to 30 centimeters apart, but I just did that
because I did not know what the proper distance between those plants
should be. I will be planting herbs and vegetables in companion
planting scheme later on, but the websites I have been looking at
don't really mention about how far apart those companion plants should
be planted, or how they should be planted. For instance, I am
wondering when you plant herbs like basil around tomatos, should basil
be planted to encircle the tomatos?
Thank you, and have a nice day.