It is usually a good idea to try to arrive during daylight hours, especially to an unfamiliar destination. I was travelling across North Africa years ago and made the mistake of arriving in Algiers at about 11pm. I stepped off the train, looked around, then stepped right back on. That was definitely a place to be mugged in. Not a good vibe.
Given that you are almost inevitably the most vulnerable when you first arrive anywhere new, it is a great idea if you can get your hotel or guesthouse to pick you up from the airport or train or bus station etc. many places offer this service for free if you stay more than a couple of nights.
It is a good idea to try to have a handful of the local currency or US dollars in the lowest denomination notes you can get; bartering for a taxi is difficult if the lowest note you have is 3 months wages to the driver!
Lastly, attitude. Look, when you arrive anywhere new, you are bound not to know what represents good value and what doesn't. Just go with the flow, accept that for the first day or two you'll 'lose' a bit of money on stuff and don't get stressed about being ripped off. Over the first few days you'll get experienced with the local currency and then it isn't a problem anymore.
Director of Online