For the US investor... Boring large index ETFs; VOO, VTI, BBUS, SCHB = 40%, maybe some small-mid cap ETFs; BBMC, SCHM, VO = 20%, some growth; SPYG, QQQ, SCHG, MGK, VUG = 30% enough cash to pay for 1-2 years of living expenses, emergencies or invest in a new career and the remaining in some kind of inflation hedge; materials, energy, real estate ETFs; FMAT, FENY, FREL. Never sell, only rebalance with new money.
Always front-load retirement contributions, contribute as much money early in the year, January 1st, if possible. Under 40, pay taxes now, let investments grow tax free, between 40-50 years old 50/50 between ROTH and Regular and depending on income (higher income more tax deferred, lower more tax now), over 50 or within 5 years of retirement, know the withdrawals penalties for pretax contributions in your plans. In the US, Rule of 55, 72t, 457, in-plan conversion, etc all different depending on company, investment firm, state and will change over time without notice and out of any individuals control... but most likely still 50/50.
Although there are 100's of calculators and individuals providing estimates, tax laws and future returns make any ROTH vs Regular estimation 5, 10, 20+ years in the future fruitless beyond wasting a few hours or confusing someone. For example, if future returns are high, ROTH 100% is preferred, if future returns are low or negative for a time in retirement, tax deferred 100% is always better. Without this future knowledge of market returns and sequence, any estimate is just waste of time. Future estimations by any tool are also fraught with stats based biases and assumptions that may not be true, normally distributed returns vs. left skew (even for a few years) will blow up all estimation tools.
I have worked in Finance most of my life and can count on my thumb, give or take 1-2, the number of people who can consistently over time even come close to matching boring index funds risk adjusted returns (with all his fame, clout, money, power, influence, connections, etc... compare Warren Buffet BRKB to S&P 500 over the past 2, 5, 10 years). You are more likely to have LeBron or Luka show up at your local YMCA for a pickup game than find a successful stock picker. Several hedge fund manager will be able to show positive risk adjusted performance over short samples of time, but usually due to hidden leverage that will blow up from time to time (see Archegos = -100% return, LTCM = -100% return, Renaissance RIEF, RIDA RIDGE public funds that only underperformed a bland S&P 500 index by 35%-47% in 2020, etc... ).
Rad above or follow below and your portfolio will be in the top 98% performance of all brokerage accounts and save 100's of hours.
https://www.youtube.com/watch?v=JdUKhgW1gOo