• Set your Heroku app's buildpack URL to https://github.com/Gertrwde/heroku-buildpack-nodejs-bower-gulp-sass.git. To be safe, you should really fork this and use your fork's URL.
• Run heroku labs:enable user-env-compile to enable environment variable support
• Run heroku config:set NODE_ENV=production to set your environment to production (or any other name)
• Add a Gulp task called heroku that builds your app
• Install the dependenies for serving the app: npm install gzippo express morgan --save
• Create a simple web server in the root called heroku_web.js:

var gzippo = require('gzippo');
var logger = require('morgan');
var express = require('express');
var app = express();

app.use(logger('dev'));
app.use(gzippo.staticGzip("" + __dirname + "/build"));
app.listen(process.env.PORT || 5000);

• Add a single line Procfile to the root to serve the app via node:

web: node heroku_web.js

Inspired by Deploying a Yeoman/Angular app to Heroku.

Forked from heroku-buildpack-nodejs-gulp.

Which was forked from heroku-buildpack-nodejs.

Heavily based on heroku-buildpack-nodejs-grunt.