working with an existing org in sfdx/vscode

deploying

//add this to your ~/.bash_profile

alias cdp="mkdir src;sfdx force:source:convert -d src;sfdx force:mdapi:deploy -w 5 -d src"

//then, when you want to deploy something to your default alias,
cdp

//The alias is setup so that you can add other flags on the end, like
cdp -u cg2 (deploy somewhere else)
cdp -c (just check that it would, but don't really deploy...useful for validation

//Sometimes I get confused between force-app/main/default/classes/myClass.cls (that I should be editing) and /src/classes/myClass.cls (which always gets overwritten)
//So I often run the alias as 
rm -rf src; cdp; rm -rf src

pulling when you setup

// let's get the all code down from a real org

//install from https://github.com/mshanemc/sfdx-msm-plugins
first, auth your org and give it a handy alias, and -s makes it the default for the current folder
sfdx force:auth:web:login -a cg1 -s

sfdx msm:mdapi:pull -u cg1 -c
// -c is for code.  It'll pull apex, VF, components, static resources, then unzip them, and convert to sfdx format