Black is usually a little too dark. Especially when applied on white armor. Grey gundam markers have done very well for me.
GSI Creos Gray Fine Point Gundam Marker https://www.amazon.com/dp/B006B3YYZM/ref=cm_sw_r_apan_i_9FRC5W8B1H0MGKBQNW3T?_encoding=UTF8&psc=1
u/TonyKebell has already given a great response so I'll just tell you my process.
BTW! Thank you!
I originally did a black wash but in hindsight I should have used a brown/orange instead of straight "flat black".
So what I did was a new color (gray) and technique.
I used:
GSI Creos Gray Fine Point Gundam Marker https://www.amazon.com/dp/B006B3YYZM/ref=cm_sw_r_apan_glt_fabc_P8ZQMJVCP9J374K1KBRB?_encoding=UTF8&psc=1
And filled in all the crevices with the gray pen and the result was a happy medium! Although it took (ALOT) longer, I think it's easier.
Oops, theres a typo in there somewhere. If you've got a few extra bucks and live in the US Amazon has a good price on the GM02 with free shipping as well. https://www.amazon.com/GSI-Creos-Point-Gundam-Marker/dp/B006B3YYZM/ref=sr_1_2?ie=UTF8&qid=1518123632&sr=8-2&keywords=Gm02+gundam+marker
Great job. Really, it looks awesome. I would agree with Rouge-Y though, note necessarily thinner panel lines, but lighter. What you have there would be great for darker plastic. I would recommend the gray panel line marker or a mechanical pencil for white and yellow pieces.
The gray panel line marker is my bread and butter: http://www.amazon.com/GSI-Creos-Point-Gundam-Marker/dp/B006B3YYZM/ref=sr_1_5?ie=UTF8&qid=1453841124&sr=8-5&keywords=panel+line
there are a few different methods for panel lining you can use a gundam marker made for panel lining like these:
or a really fine tip marker (like 005 point at least) but i'm not sure what brands to suggest i've also heard of panel lining with pencil but have never tried it so i can't say if it works or not and finally there is panel washing which i just suggest if you're curious about that to like look up "panel wash" on youtube
This marker is probably all you will need for a while, as long as you are gentle with the tip.
If you have a hobby shop nearby, it might be easier (and probably cheaper) than Amazon. The grey marker brings out panel lines and shadows best on white, grey, and lighter blue/green colors. All you need to clean up the lines is a Q-tip and a tiny amount of butane/lighter fluid.
However, once you get into the hobby more and are building more (1-3 models per month, in my estimate), you may want to invest in a pre-mixed set of panel washes for use on different colors.
I got a set of these, I don't think they were from Amazon, but here's the amazon link. https://www.amazon.com/dp/B006B3YYZM/ref=twister_B07TY8ZTY2?_encoding=UTF8&psc=1
Are you talking about this?