Manual exposure may be necessary now and then, but aperture priority with exposure correction will generally give you adequate control over depth of field and exposure. When in doubt, bracket . Composition Keep it simple. Shoot tight with a clear subject in mind. Collections of flowers may be breath-taking in person, but they tend to lose a lot of their punch in photographs.
Good composition makes up for many sins.
A monopod can be very solid if you sit down with it. In hilly areas, mornings are usually calmest. If you're stuck shooting with a breeze, patience, a fast lens, a ready camera prepared with a half-press of the shutter release and multiple exposures often pay off. You'll quickly learn where your eye and camera disagree about flower colors, and your field notes will guide your color corrections at post-processing. In my limited experience, it's not always possible to correct all the inaccurate colors at once with flowers, even with tone curves or equalizations applied to each color channel separately.