Oliver Glasner closed the curtain on a transformative spell as Crystal Palace manager with a third trophy in a year after they lifted the Conference League title by beating Rayo Vallecano.He leaves having developed the Eagles beyond recognition, taking them from underdogs to believers, and he has delivered Europa League football for next season, a major draw for prospective signings and the club’s next manager.So, following Glasner's incredible tenure, here are three things Palace must do to build on his success ahead of a busy summer.Be bold and decisive in the market ‘We have got a taste for it now, we want to keep it going,’ owner Steve Parish said after the Rayo win. 'We have gone up a level and we have got to try and stay there.’This triumph has given Palace a superb platform, but they cannot repeat the same mistakes of recent summers.Reinforcements have tended to come in late in windows, a regular bugbear of Glasner. Oliver Glasner gave Crystal Palace fans the perfect farewell by winning the Conference League It was a fitting way to mark the end of Glasner's transformative tenure at Selhurst ParkBefore this season, only back-up left-wing-back Borna Sosa and reserve keeper Walter Benitez joined, leaving a desperate rush towards deadline day when Yeremy Pino, Christantus Uche and Jaydee Canvot came in. Evann Guessand and Jorgen Strand Larsen also arrived late in the winter window.Uncertainty over the futures of Eberechi Eze and Marc Guehi similarly proved distracting, with news of Eze’s departure breaking on the eve of Palace's Conference League debut and Guehi’s Liverpool move dramatically collapsing in the final hours of the summer.As Glasner referred to in regular outbursts, he felt the club didn’t give him enough backing after winning the FA Cup, and Palace’s squad depth was brutally exposed during the winter months when their season threatened to descend into turmoil.Parish must show lessons have been learned and he needs to act decisively on players likely to attract interest, including Adam Wharton, Maxence Lacroix, Jean-Philippe Mateta, Ismaila Sarr and Daniel Munoz.Daily Mail Sport understands Middlesbrough’s Hayden Hackney and Celta Vigo defender Oscar Mingueza, who Aston Villa also like, are two potential early targets, alongside Will Osula - although his mooted £40million price tag is likely to be prohibitive - while returning loanees, such as Danny Imray, will have a chance to impress in pre-season.Parish is not keen for major change within the squad, yet he must make sure the new boss has the tools to deal with another potentially gruelling campaign, with midfield likely to be a particularly important area to replenish given the uncertainty over Wharton and Daichi Kamada, who is out of contract.The £21.5million prize money for winning the Conference League, plus the revenue boost from Europa League football, should help on this front. Palace chairman Steve Parish (pictured right, with Glasner) has a busy summer ahead of him Get the managerial situation sorted ASAP It is no slight on Palace that they haven’t named Glasner’s replacement yet given Wednesday's victory changes so much.Without it, there would be no European football at Selhurst Park, yet now they can set their sights on a significantly higher calibre of players (and manager).But, while Palace will have a large contingent at the World Cup this summer, evidence of how far they have come, they need to get the new man in as soon as possible.Andoni Iraola is the clear top target, yet if he turns down Palace’s ambitious approach, they must pivot quickly to give Glasner's replacement the best possible chance of success.Whoever takes the role should do all they can to build on the unity, high standards, indomitable mindset and knack of winning big games that Glasner developed. Andoni Iraola is Crystal Palace's No 1 target but he is yet to make a decision on their interestStay patient Glasner leaves behind an incredible platform and Palace have never enjoyed more prosperous times.But that also brings a weight of expectation for the next manager, and there will be inevitable dips.With the step up to the Europa League, coupled with Palace's early Conference League struggles, expectations may have to be slightly tempered.There will also be a period of adaptation for Glasner's replacement. His players perfected his three-at-the-back system, a formation that Iraola, for example, doesn't use.That tactical change, along with the psychological side of Glasner's exit, could take time for the squad to process.Patience will be essential, as illustrated by Iraola’s slow start at Bournemouth, where he took just three points from his first nine games.Palace must support the transition to ensure the club can sustain this remarkable era.