Less is more
Just because a product has 1001 features, does not mean it is more saleable. On the contrary, it’s confusing! One great way to get users to use your system is to have focus. Take your core feature and make them extremely apparent. What If I have a lot of features? Condense I say! If you have a less tech savvy or a very busy client, the last thing they want to do is open their pocket book, give you money, and then learn how to use new software. Put the thing they are going to use on the first screen, reduce the clutter, and put the extra features in a convenient and tucked away place.
Don’t assume it’s easy
I’m a developer; everything I make is “easy” right? And sometimes you just didn’t bother to research your users. Everything can look perfect on paper, 9/10 people think it's great, but that end user will ultimately determine the feasibility of your product. Are you targeting the general public? Less tech minded individuals? Programmers? It's key to outline your audience before hand, we’ve made that mistake, and it hurts. User Interface design says that you should design for 95% of a population. They also say, if you design for every single person I guarantee you one of two things will happen, those being: failure or having a mental breakdown. Although I cannot attend this is the only cause, and shooting for 95% of the population where they say “90% are idiots” may just end up pushing you over the edge anyway.
Consistency and Obviousness
This is getting down into details, and this affects conversion like nothing else. I daresay, it will affect your product more than the product itself! It is also the hardest thing to get right. You want your users to go to your webpage/application and immediately, without thinking, know exactly what to do. I may be speaking for myself, but I’ve gone to many webpages and apps not knowing at all what to do. I’m also extremely lazy; they just lost a potential user. Make things that you want to be looked at first big, obvious, giant and bright! We did this to our sign up button and signups went up dramatically! The stupidest things can have the largest impacts. If you right align one thing, right align everything. Why? Because that one right aligned thing will attract attention, unless that is what you were going for… This is the hardest thing to measure, and the big guys spend millions of dollars on it. We are cheap, so lets take some of their hard work and put it to use!
Iteration is key
When you develop anything you will never ever ever get it right the first time. If you are a startup, your best bet is to throw out something working to get feedback as fast as you can to make your next release. Waiting until something is done, just to have it be completely wrong is a horrible waste of time. Especially when startups need to race the world. All you have versus the big guys is drive and a community that will not set fire to your building after a bad release. Sometimes I like to think of your prototypes and new features as spaghetti, it just has to stick! But, you should only do this until you have direction. Doing it too many times and your users may actually set fire to your building.