Do you diversify between similar options within your companies 401k plans?
As an example, I have 90% in a large US equity index fund, 5% in bonds and 5% in International.
There are several options in the 'Large US Equity' category...the main differences I see are fees and diversification among industries.
I also have the following option categories:
Growth
Balanced
Mid US Equity
Small US Equity
International
Specialty Sector
I find the options a bit overwhelming personally but with contributing the max, I want to ensure I am allocating properly.
Do you have any tips on how I should diversify among these categories or go about allocating my contributions in general?
You can go down this rat hole pretty far. Personally, I believe simplicity and straightforwardness win the day when it comes to investing. Don't even bother with sectors, you'll always be in the wrong one. You mentioned there is a large US equity index fund. That's where the bulk of your money should go. If you do just that, you will damn near hit a home run investing-wise.
Now, index funds are almost always cap-weighted, so in reality you are placing most of your investing dollars in a fairly small number of companies (the companies at the bottom of the index make up such small percentage they almost don't count). Plus, mid-cap and small-cap companies tend to grow faster (but with more volatility), so you'll probably want to have some money in a mid-cap or extended market fund. Your 5% in foreign funds isn't a bad idea either.
So maybe something like 60% large cap index, 30% mid-cap index, 5% foreign, and 5% bonds. Something along those lines.