I recently graduated with a dual BS/MS degree that my school offers. I am considering going to grad school for a PhD in the future, and I am considering applying sometime this fall after taking the GRE/PGRE and getting recommendation letters set up. My question is that if I am looking to get a PhD in particle theory/string theory/grand unification what should I be doing in the meantime? I right now am looking at jobs in modelling or data science in the meantime because I have a few good opportunities in them around me, but I'm not sure if I should be looking at other types of jobs while I wait. If I'm going into theory should I be looking to do some part time teaching (which I'm qualified for as I have an MS) or should I be looking for jobs that are similar to engineering, or will any quantitative job do, so long as my application looks strong enough?