Shaving down there.

For everyone that shaves down there. Waxing is too expensive so I can't do it. So I shave. But does anyone have any technique advice to help me? 
My issue when I shave whether it's just the bikini area or the whole downtown area is that the next day I get all red and bumpy from where the hair grows. And every single time I get loads of ingrown hairs. It's so frustrating and so unattractive in my opinion and hate having grown up time with hubby when it looks red and bumpy down there. Or hate going to the pool or beach because my bikini area is red and bumpy. I end up wearing shorts and even go into the water with them. 
Does any one have any techniques to avoid this? And I know trimming is an Option but I need techniques for when I want to be completely hair free no trimming. 
Thank you so much in advance. And Idk if it's TMI if it is I'm sorry.