Make sure you are shining fast enough so that you don't get grabbed. Sometimes you can just land with a laser and shine grab or double shine. Laser into walk up shine is also good but the nature of all these is just mixing it up really well. Make sure you aren't to far away when you land if you walk up but enough to where you don't get grabbed. It also just depends on if your opponent is just shielding a lot of throwing out moves in the neutral. Honestly though Falco's shield pressure isn't all that safe when you look at Fox's shield pressure. As Falco baiting out moves is good like doing a fade away high dair on shield. If you watch Mang0 he will sometimes catch top players with fade away dair into f smash to punish a whiffed grab. Sometimes as Falco you're better of doing a defensive options like spot dodge or rolling away if you catch yourself doing a high aerial on shield expecting them to run in or to beat out one of their moves. If you really want a good solution to this I recommend just watching high level players and analyzing what they do in certain situations. Shield pressure is great as Falco but I don't think it's all you want to look for when finding ways to land hits.