So what's involved before Pilots attempt a landing?
Landing a jet aircraft requires a well coordinated and planned multi-crew effort. During the cruise, pilots will try to obtain destination weather or ATIS prior to planning the required approach. Sometimes things are straight forward and this involves a precision approach in good weather, however this is not always the case. On the other hand certain airfields are not as equipped so it could mean a complex circling approach into a limiting runway. In marginal weather conditions pilots then also require to have a plan B in case things don't go as planned.
Other factors that can also be limiting include crew training, aircraft capability, fuel and airfield type. All these come together to play a big part on the pre-landing briefing pilots will do before commencing decent. Sometimes certain major airports are also equipped with multiple landing runways with precision approaches and in this case, a missed approach or go-around during an approach allows other return options onto a different runway. In such airfields wind factors are not as limiting as runway courses available are multitude. Wind, cloud base and visibility play a big part in the approach outcome. If an approach is started but the weather is below the approach minimum requirements then of course this leads to going around and following a missed approach pattern. If visual contact with the runway is established and all the rest is within limits e.g. Wind factor, then the approach is continued. An exception to this is when an automatic landing is done without a requirement for visual contact however in this case both aircraft and airfield need to be equipped and crew trained to perform such a low visibility approach.
Sometimes an approach has higher requirements and is less precise. Such non precision approaches include e.g. VOR/NDB, RNAV, LOC ONLY etc type approaches. They have a higher minima for weather conditions such as cloud base and visibility and require visual contact with disconnection of auto-pilot before reaching a so called decision height. After this point the remaining approach is flown manually.
As there are several different procedure types available and all depending on various factors, the combination of all this plays a crucial part in pilot decisions and redundancy plans.
Other factors such as remaining fuel also play a large part to how many times or types of approaches pilots can attempt before required to divert to an alternate airfield with guaranteed weather for the intended approach there. In perfect weather conditions nothing can be limiting as an approach can always be flown visually. Only a technical issue affecting landing distance with a short runway may cause issues but apart from that if all stays well then it is not usually a problem. Technical problems with an aircraft can limit for instance its approach capability and/or landing distance required. It is of course rare to be thrown with both cases in one instance but even then pilots as mentioned before will have a plan B and C. Such plans and decisions are planned way in advance and so it enables the crew to be ready for any unexpected scenarios.
To summarise it all, airline pilots will take several factors into planning and considering an approach for landing. This includes: approach type, aircraft capability, weather, crew training, fuel available, performance issues e.g. Landing distance and redundancy in case of airport issues or technical problems. Plan A is always to land at destination however in aviation a plan B and C is vital in a safe overall operation.