I have some general criteria: less than $100k, not-location depended, preferably b2b, not physical product ect.
I presume that is $100k USD per investment, not in total?
Early stage tech investment is a numbers game, in that the rewards are potentially great but the number of failures is high. Startups are defined differently to regular businesses because of their attempt to grow unfeasibly quickly. That's why angel and VC capital is needed, to short-circuit an extended growth time, as a regular business would. Not surprisingly that means risks increase.
With that in mind, understand what sort of investment portfolio you want (and the risk you're willing to assume) will help decide how you invest your money. If you want to advise and even be hands-on, geography will be important.
You could then look at syndicates on Angel List (though these require some consideration as they vary in quality, unless you put your funds in a syndicate of syndicates from a more experienced syndicator), going direct to startups (though this is time and knowledge intensive) or one of the many crowd funding platforms.
There are also people -like myself- who have clubs or networks of high-net worths looking to invest on deals together. Happy to discuss further if you wish.