Working for yourself has a lot of enormous benefits, but it also comes with some of the headaches our salaried counterparts don't have to deal with. One of them is not having an HR department to go to when you need help with benefits.

A key benefit you may have struggled with is funding your retirement savings. Do you stick with your IRA? Open a Solo 401(k)? 

As with most things in finance (and life), the best plan really depends on what you need. With that, what's your goal? Let's find the best plan for you. 

I want to balance simplicity with high contribution limits 
To balance simplicity with high contribution limits, consider a SIMPLE IRA. It's a lot like a SEP IRA if you don't have employees, except that it offers higher contribution limits.

Your individual contribution maximum is $12,500 for 2015 ($15,500 if you're over 50), and the employer match can be up to 3% with a further maximum of $12,500. You'll also still retain the ability to contribute to your individual IRA, which you can't do with a SEP IRA. 

I want to maximize my contributions 
If you want to get the most juice out of your retirement plan, from a tax-savings perspective, anyway, you'll want to take a look at the Individual or Solo 401(k). 

These plans give you the usual 401(k) employee contribution of $18,000 for 2015 and a tax-deductible employer contribution of up to 25% of compensation. Together, the employer and employee contributions are subject to a further maximum of the  lesser of 100% of your compensation or $53,000 ($59,000 if you're over 50).  

Put simply, between yourself as employee and yourself as employer, you can set aside as much as $53,000 to your Solo 401(k) -- if you earn enough. Oh, and you can still use your individual IRA.

I want to minimize penalties if I raid the account 
Of course, taking from your retirement funds is generally an inadvisable cash-flow management strategy, but let's face it: Sometimes things happen.

If you're looking to maximize flexibility, consider the Solo 401(k). These accounts can come with the option to take up to 50% of your balance, up to $50,000, as a loan. You might also be able to take hardship withdrawals, or pull money for other specified event noted in the plan document. 

Be sure to review the plan document and your provider's policies, however, as not all plans offer these features. 

You can also take withdrawals at any time from SEP and SIMPLE IRAs, subject to the usual penalties. Beware, however, that if you could face a 25% penalty if you withdraw from your SIMPLE plan within the first two years of participating. 

I want a Roth option 
Unless you also have an individual Roth IRA, the Solo 401(k) wins here. Provided your 401(k) provider allows these activities, you can make employee Roth contributions to shelter your future self from income taxes. 

If you're able to, contributing after-tax dollars is a great way to set yourself up for the massive success you will hopefully be enjoying later on. All withdrawals from a Roth account are generally tax-free after 59.5 years of age as long as you meet the requirements, so if you're projecting a big rise in income over time it's a great option. 

However, keep in mind that not all Solo 401(k) providers offer a Roth option, and remember that once your plan reaches a certain size there's a little more administration to be done in comparison with other plans. 

I procrastinated and forgot about 2014
For those of us who ended up a bit behind the ball on this one, you might want to consider a SEP IRA. The deadline to open and contribute to the plan is your tax filing deadline -- so if you file an extension you could conceivably put it off until October. 

SEP IRAs can take up to 25% of your net earnings for a maximum of $52,000 for 2014. In other words, they don't always offer the highest contribution limit, but now that you're thinking about these matters anyway, you can always get started on setting up your Solo 401(k) for 2015. 

But don't procrastinate! Do it now is a good mantra for any business owner to adopt, and I'm now repeating it several times daily.

But wait: Some caveats
All of these situations assume you don't have employees, and for the most part, I'm assuming you're under 50 years old. If those don't apply to you, consider speaking with an advisor, or doing a bit of extra research. If you have employees, your priorities about employer contributions might change accordingly, and if you're over 50, you might want to think about setting up a defined benefit plan for yourself.

Also, be sure to do your due diligence on plan providers. Each provider has different policies related to fees, investment options, and features such as a Roth option on your Solo 401(k). Take the time to get an understanding of these features before you sign up with a particular provider.