What Makes For A Good Tiny Leader?

I think it really depends what you intend to do with it. In a format that tops out at 3CMC it's a solid 3/2 and has the magic words of First Strike and Vigilance which do make life easier to keep it around for a while. I'm not the greatest fan of this particular heroic trigger as I prefer the more permanent nature of Phalanx Leader's +1/+1 counters - however it's a pump with trample for everyone until the end of turn.

The card lends itself towards a play style that pumps out loads of little dudes (and boy do you have a choice of nice little dudes in those colors) and then uses combat tricks to buff them up and force lethal damage through. If you build around the idea of doing that then Anax & Cymede could be quite effective as a commander. Red and white are colors that give you Haste and Tokens as well as lots of 1 mana pump spells and protection spells (Titan's Strength / Brave the Elements as recent examples) which can pump your attackers. A deck running these guys could also work reasonably well with the smaller bestow creatures and more conventional auras such as Madcap Skills. Attacking en-masse in these colors also works well with Battalion from the RtR set and especially with Legion Loyalist / Frontline Medic.

Back to your question though. What other options are there and what are the ways to know if you have found a solid and decent commander?

Well the answer to this is based around your own perception of the card. What exactly do you want a deck to do and have you got (or are you prepared to go and get) the components to make the deck do it?

My current TL is Vorel of the Hull Clad

He's a big enough body to live through most of the cheaper burn spells and even block if he has to. His ability almost screams "What can I abuse this to do?" - which is why I chose him. The answer of course is "Make very big hydras, put +1/+1 counters on Invisible Stalker and keep increasing them and also make lots of mana and punish you with it" so I've built a deck around doing that - by going out and getting some nice big hydras, Shrine of Burning Rage and some means of putting +1/+1 counters on a creature. So for that deck he is ideal.

For me Vorel seemed to present a very definite direction in which a build could go and also seemed to suggest the type of tools that would be of most use to put with him. 

I think when evaluating a potential Tiny Leader you need to look at the following areas:

1. Does it's butt look big in this?
What type of body does your potential commander have? is it a 2/2 that will die to most burn and almost anything else that blocks it or is it a 3/2 First Strike that will kill most smaller blockers (but still die to burn) or is it a 1/4 that can't attack for toffee but is hard to remove via damage.

2. How do you do what you do to me... (I wish I knew)
What 'trick' does your general have? Is it a static effect that buffs creatures or causes things to happen simply because it's on the battlefield or is it a triggered ability of some kind - if so what is the actual trigger for it? Does your commander want to attack your opponents in order to win or is it essential that it stays un-molested in order to perform it's party piece? 

3. How do you like it baby?
Knowing the answer to (2) above you should know what type of deck you would want to build around it. If you commander likes to attack or has a triggered ability like Heroic then can you build - in the colors of your commander - the type of deck that will consistently make use of those abilities? In the case of White / Red Heroic the answer is 'absolutely yes'. 

If, on the other hand, your commander likes to sit back and do things with activated abilities / tap abilities then can you build a deck that will protect it for long enough to let it do that consistently? Can you either find ways to protect your commander from removal (counterspells / artifacts) or can you generate so many other threats that your opponent always has something more urgent to kill (hydras!!). An example here would be Nin, the Pain Artist - can you build a deck that can generate massive amounts of mana through combos etc in order to let Nin either act as a sniper and pick off your opponents creatures or simply 'go off' and make them draw their whole library in one go?

4. Do you have a sister?
So knowing that you should have an idea of the types of card you would want to stock the deck with in order to make your commander 'useful' and here is the point where you can start evaluating your potential general properly by asking the following questions:

• Are the types of card I want to use legal in TL? (up to 3CMC / not banned)
• Are there enough of the relevant card types to justify making the deck (One instant kill combo, no tutors and 30 counterspells is not a deck)
• Have I got / can I get the cards I need...?

5. So, can I show you a good time?
By now you should know what you want your commander to do, how they go about doing it, what cards you will need to help them do it (CONSISTENTLY) and if you can actually get those cards to make the deck. So there is only one more question to ask: Does the idea of using this card seem like fun?

This is what it comes down to - having evaluated the deckbuilding process that would be required do you still want to play this deck with that commander? I won't play several commanders - some with really good potential - simply because I don't like the card art or the name of the card. Sounds shallow but your decks in formats like these are always an extension of yourself to some extent and if you aren't going to enjoy playing them and have fun then there is no point in even starting to build it.

So that was a little about evaluating a commander - it wasn't a truly 'nuts and bolts' evaluation but more a comment on thought processes. The other part of your question was about alternatives and that is actually easier. If, rather than looking top down (finding a card and deciding about building around it) you simply know WHAT you want to play but not which commander to play with then it gets easier.

In that case you simple evaluate the type of deck you want to build - right down to the really basic sentiment of "I want to build an aggressive Red / White deck" and then you can use Gatherer to look up your potential commanders in those colors before removing any that don't fit with the deck you have in mind. Those that are left can then be scrutinized as above but with the added knowledge that you already know what you want your deck to do - you just need to know if your commander can enable that or not.

I appreciate this was a bit general and may not have helped all that much but surprisingly it is the method I use for evaluating Tiny Leaders and EDH Commanders.

Sorry 

Pretty much yes - find a few cards that you REALLY like, for whatever reason, then work out what you could construct around them. If it's viable do it - it'll be fun