So you have your Roth IRA set up (see https://theinvestmentnerd.com/roth-or-traditional-ira-the-eternal-question/ for a discussion on why a Roth versus a regular IRA). Your next question might by how much and how often should you contribute to your account?
So how much? In general the rule of thumb is the maximum amount that you can, that amount changes from year to year and the amount for today can be found here: https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-ira-contribution-limits But that is often easier said than done for most people with a middle class income. Any tax deferred account contributions you make should be balanced against the other aspects of your financial life. In the post 6 Steps to Financial Freedom we discussed the sequential steps of how you can create your financial freedom. One of those elements is an emergency fund. If you don’t have an emergency fund, be careful contributing to your Roth IRA or 401k before your emergency fund. I would prioritize the emergency fund before the tax deferred account, because the emergency fund is the ultimate flexible tool when something unexpected happens. If you don’t have an emergency fund and put all your funds into a tax deferred account, there may be issues with getting access to the funds or penalties that you’d need to pay.
If you have your emergency fund, then you would try to max out your contributions as much as possible. One reason for this is that as you progress in your career, you may start earning too much money to use this tool anymore. There are income limits and at a certain point you cannot participate in these accounts anymore (there are complex work arounds but that’s a topic for another time). You may be very happy with yourself in the future because of the contributions you’ve made in the past if that occurs, not to mention the potential for the compounding returns in the meantime.
So how often? This question is a little easier. It honestly doesn’t matter all that much. The easiest and safest bet is just to set up a monthly transfer that occurs after you get paid. Then it’s gone, and out of sight out of mind from a spending perspective. If you have more seasonal income, then do your best to contribute when times are good, it will feel like less of a sacrifice. If you can though, just go with a regular amount with regular timing like weekly or month. It will become part of your routine and make it easier to continue doing it over the long term which is the most important part of saving.