I am a female and have worked with contractors many times. What I find is that respecting their knowledge, while giving them directions is the best approach. For example- "I realize it is difficult to maneuver into that spot and I am giving you a 2ft space to drop a tree or dig a trench... You think you can do it without hitting that tree? They will tell you why if you ask. Never expect an excavator to inherently grasp that the tree is important- they rip stuff out for a living. I stand close but don't interfere constantly. This issue is not gender related though it feels that way because you have to be blunt and clear with instructions and this can be harder for women. I also tend to their needs - no one works here without the offer of coffee, occasionally a snack - I am a horrible cook and I tell them up front - when you treat them as humans on their level you get better responses. I never whine - "hey , remember those are valuable plants - get your big ass off them." when they step on them, works well. It is communicating with them on their level- it is hard work they appreciate the honesty and the fact that I am not just a queen bee ordering them around. (not saying you are). If they by chance say sexist things- call them on it. WTF did you just say? I am actually liked, never called a bitch twice lol. I was raised in a construction family so this is easier for me.