Since I've spent the past year+ working out and taking herbs and such, I've gotten into the habit of making mini goals for myself in my head. Rather than trying to picture how I'll look years down the road, I instead picture the little changes that will happen over a few months time depending on what I'm doing at the moment. It helps me keep a more realistic view of myself and these changes, and also keeps me from getting too discouraged if I don't look how I thought I would.
Since my face is already quite androgynous and people have always told me I'd make a hot guy, I picture little changes that might occur on T such as a thicker neck and a stronger jawline, rather than trying to picture a completely different face. Sometimes I'll flex in front of a mirror topless and picture myself after top surgery (since my breasts are more masculine-shaped, it's easier to see my chest contour underneath--I think if I had more female breasts I'd have a hard time picturing this).
Just from what I've seen from other FtMs after years on T, I'm confident that I'll look fine a few years from now, and very male, so I don't worry about the long term so much as the short term.
I'm not sure what side of my family I'll closer resemble in the end. People always told me my face resembles my dad's side of the family, and I have my mom's side of the family body. But quite honestly I have trouble seeing family resemblances in people (especially in my family where both sides are strongly Italian and Irish), so I have no idea what family my face looks closer to. :/ So I don't go by that at all. Plus, my dad's really fat, and I am not at all, sooo...I don't think I'll ever look like him.