Go After Objectives
Unless you’re playing team deathmatch, Battlefield 1 is first and foremost an objective-based game. Because of this fact, it’s in yours and your team’s best interest to focus on the objectives, especially in modes where the attackers have a limited number of lives. It’s all well and good to rack up a few kills now and again, but to succeed you’ll need to capture points, flags, pigeons or whatever else it may be.
By and large focusing on objectives and capturing points is going to lead to more points for you, and in turn more experience. Thus, this is only beneficial to you.