For long term connections I use butt splices. Good butt splices and a good crimper makes a huge difference in the quality of the connection. A good crimp should survive a pretty significant pull test. I ran across an article years ago and IIRC red butt splices should be able to survive a 10 lb pull. Yellow crimps should survive 25lb plus pull test. I'll try to find that article and post a link.
They don't sell any good splices at the local hardware stores. You can find them at electrical supply houses and online. I use 3M nylon butt splices.You can see through the jacket of a nylon insulated butt splice and the good ones are likely .25-.50 each.
As far as tools, I've bought some dedicated ratcheting crimpers with interchangeable dies and they are good for heavily involved projects where tons of crimping is done, but they don't last long in my toolbag before they are removed for a more space efficient tool. Klein makes the 1005 and they are some of the best "multi tool" type crimpers that also serve as wire cutters. They do have a newer model that has a built in stripper and they seem to crimp OK too, they are just not finished as well. I just put a set of snap on crimpers in my bag but they are very similar in design to the klein 1005s, except they have the insulated crimp closer to the end.