WIRING NIGHTMARE

I'm gonna start rewiring my 73 Scamp just under the hood for now, from the fire wall forward. Everything works just fine but by the looks of it something will short out soon and can't afford a new wiring harness I think the price was 800** for the kit so I'm gonna try to build my own harness. It looks pretty simple but I've done things that look simple and found out it's harder than it looks. Sooo any ideas would be a great help.