My default basic nginx.conf that I base most of my setups around. References external configs and site files. The idea is to keep it modularized and easy to read.

nginx.conf

user			www-data;
worker_processes	auto;

error_log	/var/log/nginx/error.log warn;
pid		/var/run/nginx.pid;

events {
	worker_connections  1024;
}

http {
	default_type	application/octet-stream;
	include		/etc/nginx/mime.types;

	charset utf-8;

	## Include enabled configurations from conf.d/conf-enabled/
	include		/etc/nginx/conf.d/conf-enabled/*.conf;

	# Set default index search options for all sites
	index index.php index.html;

	## Logging options
	log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
		'$status $body_bytes_sent "$http_referer" '
		'"$http_user_agent" "$http_x_forwarded_for"';

	# Turn access logging off by default (for performance)
		#access_log  /var/log/nginx/access.log  main;
		access_log off;

	# Upstream PHP backend (enable if needed)
	#upstream PHP {
	#	server 127.0.0.1:9000;
	#}


	## Include enabled server-blocks from sites-enabled/
	include /etc/nginx/sites-enabled/*.conf;
}

Config settings such as SSL settings are kept separate from this file for readability and ease of updating/reusing. I keep them in /etc/nginx/conf.d and symlinked to /etc/nginx/conf.d/conf-enabled. A working example SSL configuration file is here