Pero al desear siempre un poco más... por allá ya vas.
"But by wanting always a little more... you're already going there."
[Captions 7-8 and 15-16, Sizu Yantra> Bienvenido]
References (such as this one) would suggest that al desear here could be translated as "when wanting" or "upon wanting," but we went with "by wanting." The idea here is that one action leads to the other, the desire in inself makes you move forward. An equally acceptable translation here would be "in wanting always..."
Al cambiar de actitud, la mayoría de la gente puede cambiar el modo en que otros los tratan.
"By changing their attitude, most people can change the way others treat them."
Al confesarle la verdad, le dio la posibilidad de evaluar la situación.
"By telling the truth, he gave her the opportunity to assess the situation."
Al dejar a aquella mujer, pudo comenzar una nueva vida.
"By leaving that woman, he could start a new life."
Final note about Sizu's Bienvenido: You will probably find captions 10 and 12, in particular, rather unusual in terms of sentence structure. These lines can have even native speakers scratching their heads and are not typical Spanish.