Some quality advice. Problem I have is that I get impatient and want to hit them or ride the entire new track. Maybe I need to build B lines first and jumps last.
While I personally don't engage in any trail building, it is my impression that this can work really well or also very poorly.
When it works well you are able to cut in new lines fast and rely on the adventurous b-line crew to bed the line in through the sheer volume of traffic. This stops the trail from growing back over while you're busy piling up the gnar!
When it doesn't work you end up with a lot of problems. The trail erodes as it gets torn up by dick heads that can't ride (especially if you haven't built berms!), jerks offs decide it must be an up trail, people claim ownership and knock down your jumps/drops/berms/whoops and other obstacles they don't like, people mistake your new line (those jumps) as their new line...and leave big panic skid marks on your launch ramp or out the back of your berm.
Alternatively you can spend hours, days, weeks, months, years working on a trail in secret. Starting in the middle, meticulously shaping each obstacle as you slowly form the trail into a work of art...only to have some simple minded pricks try and steal and finish it as a trail for simpletons. If you survive this you then face the b-line crew again thinking it is their right to skid down or up your trail because...well fuck it the trail is here and even though I have no chance of hitting that 5m gap and there is clearly no b-line I'll just trample over this kicker and ride on through. I deserve this!
It's a fucking mixed bag and the more you build the more you repair. The better the stuff you build = the more people will want to ride it. Sad fate.
Again though I don't engage in any trail building, so am just guessing that these things might happen. My only trail building experience has been on private land many many years ago.